Zaleplon is used for treating people who have trouble falling asleep. It facilitates relaxing the centers of the brain and helps the person to fall asleep.

Overview:

Zaleplon is a nonbenzodiazepine hypnotic that comes under the pyrazolopyrimidine class. N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]-N-ethyl acetamide is the chemical name of Zaleplon. Its empirical formula is C17H15N5O, and its molecular weight is 305.34. Zaleplon is a white to off-white powder that is almost insoluble in water and sparingly soluble in alcohol or propylene glycol. Zaleplon is used to treat insomnia for a short period. Insomnia is a condition where a person has a problem falling asleep. Zaleplon does not help the person to sleep longer or decrease the number of times that they wake up during the night. Zaleplon comes under the class of medications called hypnotics. It works by relaxing brain activity to allow sleep.

How Does the Zaleplon Work?

In the central nervous system (CNS), there is an equilibrium of the excitatory effects of the glutamate receptors and the inhibitory effects of the gamma-aminobutyric acid receptors (GABA). In the central nervous system, GABA exerts its effect via ionotropic GABAA and GABAC receptors and metabotropic GABAB receptors. Almost all sedative-hypnotics used in the treatment of insomnia target the GABAA receptors. The GABAA receptors contain alpha, beta, and gamma receptors in the vast majority of the 2:2:1 stoichiometry. GABA released from the presynaptic neuron activates the ligand-gated ion channel to increase chloride ion permeability, conducting hyperpolarization of the membrane and a reduction in the excitability of the neuron.

Benzodiazepines and Z-drugs (benzodiazepine derivatives such as Zopiclone, Eszopiclone, Zaleplon, and Zolpidem are the 'Z-drugs';) act via the so-called Benzodiazepines binding site located at the interface between a- and c-subunits and thereby specifically bind to gamma-containing receptors. They are positive allosteric modulators, i.e., they improve the GABA-induced chloride current, herby mediating phasic inhibition. Zaleplon, a pyrazolopyrimidine hypnotic, binds to the benzodiazepine type 1 site on the gamma-aminobutyric acid subtype A (GABA-A) receptor/chloride-ion channel complex.

Zaleplon has selectivity for specific benzodiazepine receptor subtypes and does not have the neuromuscular relaxation or anticonvulsant effects of standard benzodiazepines. Zaleplon has a rapid onset of action and a peak plasma concentration and an elimination half-life of approximately one hour each. The better action is on sleep induction than the maintenance of sleep could be explained by its short half-life and quick onset of action.

How Is Zaleplon Used?

The medication guide should be provided by the pharmacist before the patient starts taking Zaleplon each time they get a refill. If the patients have any questions, consult the doctor or pharmacist. Zaleplon is the medication to be taken by mouth as directed by the physician. Zaleplon works very quickly, so it is necessary to take it just before or when it is time to get into bed. The physician will work with the patients to find the smallest dose that works for them.

Zaleplon should not be used to take naps. The person should take a dose of this drug unless there is time for a full night's sleep of at least seven to eight hours. If the patients wake up before that, they may experience some memory loss and may find trouble safely doing any activity that requires alertness, like driving or operating machinery. It is advised to eat a very heavy/high-fat meal within two hours before taking this medication since this may prevent the drug from working properly. The medication dosage is based on the medical condition, age, and response to therapy. As this medication is usually prescribed for a short time, the physician will advise the patient when to stop taking it or when to reduce the dose.

Dosage:

For Oral Dosage Form (Capsules) For Insomnia:

In adults, 5 or 10 milligrams (mg) once a day at bedtime. The physician may adjust the dose as needed and tolerated. However, more than 20 mg per day should not be taken. In older adults, five milligrams once a day should be taken at bedtime. In children, the physician decides the use and dose of the medicine.

Dosage Form:

For oral dosage, the medicines come in the form of capsules.

The Direction of Administration:

Zaleplon should be taken immediately before bedtime or after the patient has gone to bed and has experienced difficulty falling asleep. Taking Zaleplon with or immediately after heavy, high-fat meals outcomes in slower absorption and would be expected to decrease the effect of Zaleplon on sleep latency.

Warning:

Symptomatic treatment of insomnia should be initiated only after a careful evaluation of the patient, as sleep disturbances may be the clinical manifestation of a physical and/or psychiatric disorder. The failure of insomnia relief after 7 to 10 days of treatment may suggest the existence of a primary psychiatric and/or medical illness that should be assessed. Worsening insomnia, the emergence of new thinking or behavior abnormalities, may be the consequence of an unnoticed psychiatric or physical disorder. Such findings have occurred during the course of treatment with sedative or hypnotic drugs, including Zaleplon. As some of the important adverse effects of Zaleplon seem to be dose-related, it is essential to use the lowest possible effective dose, specifically in older people.
Several abnormal thinking and behavior changes have been documented to have happened in association with the use of sedatives or hypnotics. A few of these changes may be characterized by reduced inhibition similar to effects produced by alcohol and other central nervous system depressants. Some other reported behavioral changes had comprised strange behavior, agitation, hallucinations, and depersonalization.
Problematic behaviors such as “sleep-driving” have been reported, and such events can appear in sedative-hypnotic-naive as well as in sedative-hypnotic-experienced persons. Even if demeanors such as sleep-driving may occur with Zaleplon alone at therapeutic doses, the use of alcohol and other CNS depressants with Zaleplon may also appear to increase the hazard of such behaviors, as does the use of Zaleplon at doses surpassing the maximum recommended dose. As there is a risk to the patient and the community, discontinuing Zaleplon should be strongly considered for patients who report a “sleep-driving” episode.
There are many complex behaviors that have been reported in patients who are not fully awake after taking a sedative-hypnotic. During the sleep-driving phase, patients usually do not remember these events. Amnesia and other neuropsychiatric symptoms can emerge unpredictably. In primary-level depressed patients, worsening depression, including suicidal thoughts and actions, has been reported in connection with the use of sedatives or hypnotics.
Patients receiving Zaleplon should be precautioned against engaging in dangerous occupations demanding total mental alertness or motor coordination after ingesting the drug, including potential impairment of the performance of such activities that may occur the day following ingestion of Zaleplon.
Zaleplon should not be taken with alcohol. Dosage adjustment may be required when Zaleplon is administered with other central nervous system depressant agents as there are potentially additive effects.
There are some patients who have had additional symptoms such as dyspnea, throat closing, nausea, and vomiting that suggest anaphylaxis. Some patients needed emergency medical therapy. If angioedema involves the tongue, glottis, or larynx, then airway obstruction may occur and be fatal. Patients who develop angioedema after treatment with Zaleplon should not be re-administered with the drug.

For Patients:

What Is Insomnia?

It is a disorder that can make it hard for people to fall asleep, hard to stay asleep or cause the person to wake up too early and not be able to get back to sleep. The person may still feel tired after waking up. Insomnia can sap not only the energy level and mood but also affect overall health, work performance, and quality of life. Insomnia is usually the result of stress, suffering, or a traumatic event. There are some people who have long-term or chronic insomnia that can last for a month or more. Insomnia may be the primary problem, or it may be present in association with other medical conditions or medications.

Things to Consider:

Before the Administration of the Drug:

The physician and pharmacist should be notified if the patients are allergic to Zaleplon, aspirin, any other medications, or tartrazine. Tartrazine is a yellow dye in some processed foods and drugs or any of the ingredients in Zaleplon capsules. Ask the pharmacist for a list of the ingredients.
The physician and pharmacist know what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products the patients are taking or plan to take. They should be sure to mention any of the drugs like antihistamines such as Diphenhydramine or Promethazine, barbiturates, Cimetidine, medicines used for cough and cold, Erythromycin; Ibuprofen; Imipramine, Ketoconazole medications for allergies such as Diphenhydramine, depression, or mental illness, certain medications for seizures such as Phenytoin, Carbamazepine, and phenobarbital; pain relievers; promethazine; rifampin; sedatives, other sleeping pills, thioridazine, and tranquilizers. The physicians may need to adjust the doses of the medications or keep the patient under observation for side effects.
The physician should be told if the patient drinks or has ever drunk large amounts of alcohol and if or has ever used street drugs or has overused prescription medications. If the patient has ever been suicidal and if ever had depression, mental illness, seizures, lung disease or breathing problems, or kidney or liver disease.
The physician should be notified if the patient is pregnant, plan to become pregnant, or is breastfeeding. If the patient gets pregnant while taking Zaleplon, the physician should be called.
The physician should be talked about the risks and benefits of taking Zaleplon if the patient is 65 years of age or older. Older adults should not generally take Zaleplon as it is not as safe or effective as other medications that can be used to treat the same condition.
If the patient is having surgery, including dental surgery, tell the physician or dentist that the patient is taking Zaleplon.
It should be known that this medication may cause drowsiness, decreased mental alertness, prolonged reaction time, problems with coordination the day after the patient takes it, blurry or double vision, and may increase the risk that the patient may fall. Extra care should be taken to be sure the patient does not lose balance and fall, specifically after getting out of bed in the middle of the night. The ability of the patient to drive or operate machinery the day after taking Zaleplon may be impaired even if the patient is fully awake. It should be avoided to drive a car or operate machinery until the patient knows the after-effects of Zaleplon.
Drinking alcohol should be avoided while the patient is taking Zaleplon. Alcohol can worsen the side effects of Zaleplon.
Tell the physician immediately if the patient experiences any of the symptoms like aggressiveness, strange or unusually outgoing behavior, hallucinations, feeling as if the patient is outside of their body, memory problems, new or worsening depression, thinking about killing oneself, confusion, and any other changes in the usual thoughts or behavior. Be sure that the family knows which symptoms can be serious so that they can call the physician if the patient is unable to seek treatment on their own.

During the Administration of the Drug:

A normal diet should be followed unless the physician tells the patient otherwise.

What Side Effects Can Zaleplon Medication Cause?

Zaleplon may cause some kind of side effects, and a few of them are mentioned in the following:

Drowsiness.
Dizziness.
Lightheadedness.
Absence or lack of coordination.
Tingling, numbness, and burning in the hand and feet.
Problems with the vision.
Loss of appetite.
Sensitivity to light and noise.
Weird sense of smell.
Painful menstruation.

A few of the side effects can be serious and may need emergency medical attention, such as

Hives.
Hoarseness.
Swollen feet, hands, and face.
Itching.
Rash.
Difficulty breathing or swallowing.

The patient should be taken to the emergency room if severe symptoms occur or the patient gets unconscious.

When and Why This Medication Should Be Used?

Zaleplon is used on a short-term basis to treat insomnia which is difficulty falling asleep. Zaleplon does not help to stay asleep longer or decrease the number of times the patient wakes up during the night. Zaleplon is a part of the class of medications called hypnotics. It works by relaxing the centers of the brain, and it allows the patient to fall asleep.

How Effective Is Zaleplon?

Zaleplon is a pyrazolopyrimidine hypnotic that is used for the treatment of insomnia. Zaleplon binds preferentially at the α1β2γ2 subunit of gamma-aminobutyric acid type A (GABAA) receptors in the central nervous system. It has a half-life of about one hour. Efficacy studies show that Zaleplon is an appropriate hypnotic for sleep initiation purposes. Yet, as it has a short half-life, Zaleplon is less effective in sleep maintenance in comparison with other hypnotics. However, Zaleplon does improve total sleep time. There were no rebound effects observed after treatment discontinuation. The use of Zaleplon is somewhat safe. Adverse effects are mild and do not last much. No important interactions have been reported, and there is no evidence of potential abuse. After four hours of Zaleplon, there were no effects on cognitive, memory, or psychomotor performance, and the ability to drive a car has been reported. Comparisons with new nonbenzodiazepine hypnotics should decide the importance of Zaleplon in the future treatment of insomnia.

How Is Zaleplon Supplied?

Zaleplon is supplied as capsules in two varieties such as:

Five milligrams opaque green cap and opaque green body with “5 mg” written on the cap and SONATA written on the body.
10 milligrams opaque green cap and opaque green body with “10 mg” written on the cap and SONATA written on the body.

How to Store and Dispose of Zaleplon?

It should be stored at a controlled room temperature of 20°Celsius to 25°Celsius (68°Fahreinheit to 77°Fahreinheit). It should be dispensed in a light-resistant container. It is important to keep all medication away from the reach of children as many containers are not child-resistant, and young children can have access to them easily. To prevent young children from poisoning, safety caps should be locked, and immediately place the medication in a safe location. The medications which are not needed should be disposed of in special ways to make sure that pets, children, and other people cannot consume them. Also, it should not be flushed down the toilet. Rather, the most suitable way to dispose of the medication is through a medicine take-back program. Talk to the pharmacist or the local garbage or recycling department should be contacted to learn about take-back programs in the community.

What Should Be Done in the Case of Zaleplon Overdose?

After the overdose, if the patient has fainted and collapsed, has a seizure, has trouble breathing, or can't be awakened, immediately take the patient to the emergency room.

What Should Be Done if a Dose of Zaleplon Is Missed?

Zaleplon should only be taken before going to sleep. If the patient did not take Zaleplon before going to bed and is unable to fall asleep, the patient may take Zaleplon only if the patient will be able to stay in bed for at least eight hours after. A double dose of Zaleplon should not be taken to make up for a missed dose.

What Other General Information Should Be Known About Zaleplon?

Nobody else should be allowed to take the medication. Zaleplon is a controlled substance. Prescriptions can be refilled only a limited number of times. It is important for the patients to keep a written list of all of the prescription and nonprescription medicines they are taking, as well as any products such as vitamins, minerals, or other dietary supplements. Patients should bring this list with them each time they visit a physician or if they are hospitalized.

For Doctors:

Pharmacology:

Pharmacodynamics and Mechanism of Action:

While Zaleplon is a hypnotic agent with a chemical structure unrelated to benzodiazepines, barbiturates, or other drugs with known hypnotic properties, it still interacts with the gamma-aminobutyric acid-benzodiazepine GABA-BZ receptor complex. Subunit modulation of the GABA-BZ receptor chloride channel macromolecular complex is hypothesized to be responsible for some of the pharmacological properties of benzodiazepines, which include sedative, anxiolytic, muscle relaxant, and anticonvulsive effects in models. Some other preclinical studies have also shown that Zaleplon binds selectively to the brain omega-1 receptor situated on the alpha subunit of the GABA or chloride ion channel receptor complex and potentiates t-butyl bi-cyclo phosphorothioate (TBPS) binding. Studies of the binding of Zaleplon to recombinant GABAA receptors (α1β1γ2 [omega-1] and α2β1γ2 [omega-2]) have shown that Zaleplon has a low affinity for these receptors, with preferential binding to the omega-1 receptor.

Pharmacokinetics:

The pharmacokinetics of Zaleplon has been investigated in more than 450 healthy subjects (young and elderly), nursing mothers, and patients with hepatic disease or renal disease. In healthy subjects, the pharmacokinetic profile has been examined after single doses of up to 60 milligrams and once-daily administration at 15 milligrams and 30 milligrams for ten days. Zaleplon was rapidly absorbed with a time-to-peak concentration (t-max) of approximately one hour and a terminal-phase elimination half-life (t1/2) of approximately one hour. Zaleplon does not accumulate with once-daily administration, and its pharmacokinetics are dose-proportional in the therapeutic range.

Absorption:

Zaleplon is rapidly and almost completely absorbed after oral administration. Peak plasma concentrations are attained within approximately one hour after oral administration. Although Zaleplon is well absorbed, its absolute bioavailability is approximately 30 % because it undergoes significant pre-systemic metabolism.

Distribution:

Zaleplon is a lipophilic compound with a volume of distribution of approximately 1.4 Liter per kilogram following intravenous (IV) administration, indicating substantial distribution into extravascular tissues. The in vitro plasma protein binding is approximately 60 percent and is independent of Zaleplon concentration over the range of 10 nanograms/milliliter to 1000 nanograms/milliliter. This suggests that Zaleplon disposition should not be sensitive to alterations in protein binding. The blood-to-plasma ratio for zaleplon is approximately one, indicating that Zaleplon is uniformly distributed throughout the blood with no extensive distribution into red blood cells.

Metabolism:

After taking Zaleplon orally, it is extensively metabolized, with less than 1 percent of the dose excreted unchanged in the urine. Zaleplon is primarily metabolized by aldehyde oxidase to form 5-oxo-zaleplon. Zaleplon is metabolized to a lesser extent by cytochrome P450 (CYP) 3A4 to form des-ethyl-zaleplon, which is quickly converted, presumably by aldehyde oxidase, to 5-oxo-des-ethyl-zaleplon. These oxidative metabolites are then converted to glucuronides and eliminated in urine. All of Zaleplon's metabolites are pharmacologically inert.

Elimination:

After Oral or After Intravenous IV Administration:

Zaleplon is rapidly eliminated with a mean t1/2 of approximately one hour. The oral-dose plasma clearance of Zaleplon is about three Liter/hour/kilogram, and the IV Zaleplon plasma clearance is approximately one Liter/hour/kilogram. Assuming normal hepatic blood flow and negligible renal clearance of Zaleplon, the estimated hepatic extraction ratio of Zaleplon is approximately 0.7, indicating that Zaleplon is subject to high first-pass metabolism.

After Administration of a Radiolabeled Dose:

70 percent of Zaleplon in the administered dose is recovered in urine within 48 hours (71 percent recovered within six days), almost all as Zaleplon metabolites and their glucuronides. An additional 17 percent is recovered in feces within six days, most as 5-oxo-zaleplon.

Toxicology:

Toxicity in a milder form can cause lethargy, drowsiness, and confusion. Severe toxicity can lead to respiratory depression, ataxia, hypotension, hypotonia, loss of consciousness, coma, and rarely death. Rare cases of fatalities following an overdose of Zaleplon have been reported, most of which correlate with the use of other central nervous system depressants. Management aims at providing supportive treatment, including gastric lavage and intravenous (IV) fluids. Researchers have conducted animal studies that show flumazenil is useful as an antagonist to Zaleplon, but there are no clinical trials regarding the use of Flumazenil as an antidote to Zaleplon overdose.

Warning and Precautions Before Prescribing:

Warnings:

As sleep disturbances may be the presenting manifestation of a physical or psychiatric disorder or both, symptomatic treatment of insomnia should be initiated only after a careful evaluation of the patient. The failure of insomnia to resolve after 7 to 10 days of treatment may indicate the presence of a primary psychiatric or medical illness or both that should be evaluated. Worsening insomnia or the emergence of new thinking or behavior abnormalities may be the consequence of an unrecognized psychiatric or physical disorder. Such findings have emerged during the course of treatment with sedative or hypnotic drugs, including Zaleplon. Because some of the important adverse effects of Zaleplon appear to be dose-related, it is important to use the lowest possible effective dose, particularly in the elderly.
A variety of abnormal thinking and behavior changes have been reported to occur in association with the use of sedatives or hypnotics. Some of these changes may be characterized by decreased inhibition, similar to effects produced by alcohol and other central nervous system depressants. Some other reported behavioral changes included bizarre behavior, agitation, hallucinations, and depersonalization.
There were complex behaviors such as “sleep-driving” (i.e., driving while not fully awake after ingestion of a sedative-hypnotic, with amnesia for the event) have been reported. These events can occur in new sedative-hypnotics as well as experienced sedative-hypnotic persons. Although behaviors such as sleep-driving may occur with Zaleplon alone at therapeutic doses, the use of alcohol and other CNS depressants with Zaleplon appears to increase the risk of such behaviors. Due to the risk to the patient and the community, discontinuing Zaleplon should be strongly considered for patients who report a “sleep-driving” episode.
As there is rapid onset of action, Zaleplon should only be ingested immediately prior to going to bed or after the patient has gone to bed and has experienced difficulty falling asleep.
The patients taking Zaleplon should be advised to stay away from dangerous and unsafe occupations that require a completely alert mental state and coordination.
The dose needs adjustment when Zaleplon is administered with other central nervous system agents because of the potentially additive effects.
Patients who develop angioedema after treatment with Zaleplon should not be rechallenged with the drug.

Precautions:

Zaleplon should be taken immediately before going to bed or after the patient has gone to bed and has experienced difficulty falling asleep. As with all sedatives or hypnotics, taking Zaleplon while still up and about may result in short-term memory impairment, hallucinations, impaired coordination, dizziness, and lightheadedness.
Abnormal motor and/or cognitive performance after repeated exposure or unusual sensitivity to sedative/hypnotic drugs is a concern in treating elderly and/or debilitated patients. A dose of five milligrams is recommended for elderly patients to decrease the possibility of side effects. Elderly and/or debilitated patients should be monitored closely.
Zaleplon should be used with caution in patients with diseases or conditions that could affect metabolism or hemodynamic responses.
If Zaleplon is prescribed to patients with compromised respiratory function, it should be remembered that sedatives/hypnotics have the capacity to depress respiratory drive.
The dose of Zaleplon should be reduced to five milligrams in patients with mild to moderate hepatic impairment. It is not recommended for use in patients with severe hepatic impairment.
As with other sedative/hypnotic drugs, Zaleplon should be administered with caution to patients showing signs or symptoms of depression. Suicidal tendencies may be present in such patients, and protective measures may be required. Intentional overdosage is more common in this group of patients, and hence, the least amount of drug that is possible should be prescribed for the patient at any one time.
Patients should be informed about every warning and precaution before starting the treatment.

Indications and Uses:

Zaleplon is suggested for the short-term treatment of insomnia. Zaleplon has been shown to decrease the time to sleep onset for up to 30 days in controlled clinical studies. It has not been shown to increase total sleep time or decrease the number of awakenings. The clinical trials performed in support of efficacy ranged from a single night to five weeks in duration. The final formal assessments of sleep latency were performed at the end of treatment.

Dosage and Strength Forms:

Zaleplon is supplied as capsules and is available in five milligrams and 10 milligrams.

Dosage and Administration:

Dosage:

The dose of Zaleplon should be individualized. The recommended dose of Zaleplon for most non-elderly adults is 10 milligrams. For certain low-weight individuals, five milligrams may be a sufficient dose. Although the risk of certain adverse events associated with the use of Zaleplon appears to be dose-dependent, the 20 milligrams dose has been shown to be adequately tolerated and can be considered for the few patients who do not benefit from a trial of a lower dose. Doses above 20 milligrams have not been satisfactorily evaluated and are not recommended.

Administration:

Zaleplon should be taken immediately before bedtime or after the patient has gone to bed and has experienced difficulty falling asleep. Taking Zaleplon with or immediately after a heavy, high-fat meal results in slower absorption and would be expected to reduce the effect of Zaleplon on sleep latency.

Considerations for Administration:

Zaleplon is a Schedule IV prescription medication. It is available in five milligrams and 10 milligrams oral capsules. It comes in capsule form with an opaque green cap and an opaque pale green body with five milligrams and 10 milligrams written with black ink on the body. The advice is to start with five milligrams by mouth, to be taken immediately before bedtime. The usual dose is 10 milligrams by mouth immediately before bedtime. It is given seven hours before the patient plans to wake up. The maximum dose can go up to 20 milligrams by mouth to be taken directly before bedtime. The maximum dose in elderly or debilitated patients has to be 10 milligrams by mouth, taken immediately before bedtime. If the provider plans to stop the medication, they should taper it down slowly.
It is considered a Category C medication and not advised for usage during pregnancy, labor, and delivery.
Not sufficient data is available on if it is suitable for pediatric patients.
A small amount of Zaleplon was observed to be present in the breast milk, it is not supposed to be used in lactating mothers.

Contraindications:

Contraindications include hypersensitivity to Zaleplon or to any ingredients of the medication. There have been reports of symptoms such as throat closing, shortness of breath, nausea, and vomiting after taking the medication, suggesting anaphylaxis. Reports of angioedema exist in patients after taking the first or subsequent doses of sedative-hypnotics, including Zaleplon rarely. Patients with a history of angioedema with zaleplon should not receive this drug. As mentioned earlier, Zaleplon is not recommended in patients with severe hepatic impairment. Lately, the Food and drug administration (FDA) has added a boxed warning to certain prescription insomnia medications after reports of injury and death resulting from complex sleep-related behaviors like sleepwalking, sleep-driving, and engaging in other activities while in a sleep-like state after taking these medicines. These new warnings will be necessary for the Z group of drugs, including Eszopiclone, Zaleplon, and Zolpidem. Contraindications to using these Z drugs, including Zaleplon, include patients who have had a history of such complex sleep-related behaviors. Central nervous depression causes impaired mental and physical impairment, primarily if used concomitantly with other drugs that cause central nervous depression.

Drug Interactions:

Ethanol: Zaleplon 10 milligrams potentiated the central nervous system-impairing effects. The potentiation resulted from a central nervous system pharmacodynamic interaction, Zaleplon did not affect the pharmacokinetics of ethanol.

Imipramine: Coadministration of single doses of Zaleplon 20 milligrams and Imipramine 75 milligrams produced additive effects on decreased alertness and impaired psychomotor performance for two to four hours after administration. The interaction was pharmacodynamic with no alteration of the pharmacokinetics of either drug.

Paroxetine: Coadministration of a single dose of Zaleplon 20 milligrams and Paroxetine 20 milligrams daily for seven days did not produce any interaction on psychomotor performance. Further, Paroxetine did not alter the pharmacokinetics of Zaleplon, reflecting the absence of a role of CYP2D6 in Zaleplon's metabolism.

Venlafaxine: Coadministration of a single dose of Zaleplon 10 mg and multiple doses of Venlafaxine ER 150 mg did not result in any significant changes in the pharmacokinetics of either Zaleplon or Venlafaxine. Also, there was no pharmacodynamic interaction as a result of the coadministration of Zaleplon and Venlafaxine ER.

Other Specifications:

Use in Pregnancy: There are no studies available on Zaleplon in pregnant women; therefore, Zaleplon is not recommended for use in women during pregnancy.

Use in Lactating Mothers: A small amount of Zaleplon was observed to be present in the breast milk; it is not supposed to be used in lactating mothers.