Overview:
Droxidopa is a drug used in the treatment of orthostatic hypotension in adults. It is a condition characterized by a sudden drop in blood pressure when an individual makes an attempt to stand. The drug was approved by the Food and Drug Administration (FDA) in February 2014. The drug is available in the form of capsules and can be consumed only under the supervision of healthcare professionals. Various studies have supported the efficacy of the drug in treating orthostatic hypotension. This article explains in detail the mechanism of action, usage, and side effects of the drug.
How Does Droxidopa Work?
Droxidopa is used to treat neurogenic orthostatic infection and other conditions related to low blood pressure. It is a precursor of norepinephrine, a hormone that is essential for regulating blood pressure and other autonomic functions of the body. The mechanism of action of the drug is mentioned below:
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The drug is converted by enzymatic reaction into norepinephrine, which is a catecholamine and is produced in the nerve endings. Once it is absorbed into the bloodstream, it is taken up by the nerve terminals in various tissues. Inside the nerve terminal, the drug gets converted into norepinephrine.
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Norepinephrine acts as a vasoconstrictor, causing the blood vessels to constrict. This increases blood pressure and improves the blood flow to vital organs like the brain and heart.
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By increasing the norepinephrine levels, the drug raises blood pressure and counteracts hypotension.
Uses:
The drug is very useful in orthostatic hypotension to improve the symptoms of low blood pressure upon standing. It is usually due to neurological disorders like Parkinson’s and autonomic disorders.
Dosage:
The drug dosage may depend on the treatment for hypotension. The following dosage guidelines are based on the recommended adult dosage:
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An initial dose of 100 milligrams (mg) thrice a day is recommended to be consumed in the morning. The first dose is usually taken after waking up and is followed by two doses at intervals of three to four hours.
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The drug dosage is gradually increased based on the patient’s tolerability. It can be increased to approximately 100 mg every 24 hours until the desired dosage is achieved.
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The maximum dosage is about 600 mg, which has to be administered thrice daily.
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Consuming the drug along with food can increase absorption and limit the gastrointestinal effects.
Warnings:
Like other medications, the drug has specific warnings, which are mentioned below:
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The drug may cause supine hypertension, resulting in high blood pressure.
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In some instances, the drug can cause a hypertensive crisis, resulting in increased blood pressure. Healthcare providers should carefully monitor the patient.
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The drug can increase the risk of cardiovascular diseases with pre-existing conditions.
For Patients:
What Is Orthostatic Hypotension?
Orthostatic hypotension is a medical condition in which there is a sudden drop in blood pressure as an individual stands or lies down. The individual is likely to experience the following symptoms:
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Dizziness.
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Lightheadedness.
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Nausea.
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Vomiting.
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Fatigue.
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Weakness.
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Loss of balance.
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Loss of coordination.
In some cases, orthostatic hypotension can result in syncope with a temporary loss of consciousness. This occurs generally when the brain cannot receive enough blood and oxygen. Other factors causing this condition are:
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Dehydration.
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Diabetes.
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Heart conditions.
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Neurological disorders.
Learn More About Droxidopa:
When and How Often to Take Droxidopa?
The dosing of the drug depends on the medical condition and severity of the illness being treated. The drug is usually available in various strengths and formulations. A starting dose of 100 milligrams thrice daily is recommended. After that, the dose may gradually increase to achieve the therapeutic effects. A maintenance dose of 600 to 1800 milligrams is given according to the individual's weight. The drug should be taken with food for better absorption.
How Effective Is Droxidopa?
The drug is shown to be effective in treating hypotension and related conditions. A drop in blood pressure characterizes hypotension and leads to symptoms like dizziness and fainting. Patients are able to remain upright without experiencing any significant drop in blood pressure.
Things to Inform the Doctor Before They Prescribe Droxidopa :
Before the doctor prescribes the drug, providing essential information regarding the family and medical history is important. It is also important to report any allergic reaction and list current medications. If the patient is a breastfeeding mother or planning to become pregnant, it is safer to inform the doctor about their health status.
How to Take Droxidopa?
The drug should be taken in oral capsules as directed by the healthcare provider. It is essential to follow the dosing instructions, and additionally, consuming the drug along with food can increase the like absorptions. Capsules are to be swallowed with a full glass of water. Avoid crushing or chewing the tablet, as it may tamper with the drug's efficacy. Do not abruptly stop the drug without consulting the doctor.
Things to Do After Starting Droxidopa:
After starting the drug intake, it is important to ensure that the patient takes the right amount of dosage. Monitoring the symptoms in the early period is crucial. Also, if there are any potential side effects, it is essential to report them to the doctor immediately. Following-up appointments can help to understand the prognosis of the condition.
Look Out for Side Effects:
A few side effects of the drug are mentioned below:
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Headache.
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Nausea.
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Vomiting.
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Dizziness.
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Lightheadedness.
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High blood pressure.
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Syncope or fainting.
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Allergic reactions.
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Urinary retention.
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Increased heart rate.
Dietary Alterations:
No specific dietary alterations are recommended unless specified by the doctor. It is essential to have a healthy diet rich in vitamins and minerals.
What Should Be Done When a Dose Is Missed?
In case of missing a dose, consuming it at the earliest possible is important. Avoid overdosing if it is already time for the next dose, as it can cause potential adverse effects.
What Should Be Done to Treat Droxidopa Overdose?
In case of overdosing on the drug, it is essential to get medical help at the earliest possible. Do not induce vomiting unless instructed by the healthcare professional.
How to Store Droxidopa?
Ensure the drug is stored properly in the original container to avoid contamination. Storing the drug at room temperature of about 25 degrees Celsius is essential. It is safer to use a child-resistant container. Store the drug in a dry place with lower humidity. It is important to keep the drug away from pets and children.
How to Handle Droxidopa?
Ensure to take the recommended dosage as prescribed. Use gloves or wash hands thoroughly before taking the drug with bare hands.
How to Dispose of Droxidopa?
Proper disposal of medication is essential to prevent accidental ingestion and prevent any environmental impact. Always follow the disposal instructions provided on the label. Contact local community take-back programs. Avoid flushing the drug into the toilet or flushing it down the drain, as it could cause water contamination.
Avoid Self-Medication:
Self-medication can be harmful and may cause unwanted complications. So, avoid taking self-medication without the doctor’s recommendation.
Tips to Stay On Track:
A daily reminder or a phone alarm can help to consume the drug regularly without skipping it. Also, taking the drug every day at the same time can make it a habit.
For Doctors:
Indications:
The drug is extensively used in the treatment of orthostatic hypotension. The drug is not indicated for use in other forms of hypotension and other medical conditions.
Pharmacology:
Drug Taxonomy:
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Chemical name - (R)-3,4-Dihydroxy-L-phenylalanine.
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Class - Alpha and beta-adrenergic agonists.
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Subclass - Alpha-2 adrenergic agonist.
Mechanism of Action:
The mechanism of action of the drug involves converting it into norepinephrine and leading to an increased level of neurotransmitter hormone. It is responsible for the fight-or-flight response. The prodrug gets converted into norepinephrine via an enzymatic reaction and is taken up by the nerve terminals.
Pharmacodynamics:
The drug gets converted into norepinephrine via various enzymatic reactions in the body. The neurotransmitter plays a critical role in the sympathetic nervous system. It activates the beta-adrenergic receptors and contributes to increased heart rate and contractility.
Ingredients:
Active Ingredient:
Droxidopa
Absorption:
The drug is absorbed via the oral route and is converted into an active form in the body. After ingesting, it is absorbed from the gastrointestinal tract and enters the bloodstream. After reaching the bloodstream, it is taken up by the nerve terminals, where it undergoes enzymatic conversion to norepinephrine, a neurotransmitter. The drug is absorbed better with food.
Distribution:
The drug is distributed throughout the body after oral administration and gets rapidly absorbed into the gastrointestinal tract. From the gastrointestinal tract, it moves into the bloodstream and gets distributed to various organs. After absorption, it undergoes active conversion into norepinephrine.
Metabolism and Elimination:
The drug is an inactive compound that usually gets converted in the body to its active form. After rapid absorption, it enters the bloodstream and is quickly absorbed by the nerve terminals, where it undergoes enzymatic conversion. The drug does not cross the blood-brain barrier. This allows it to improve blood pressure without affecting the central nervous system.
The drug is eliminated from the body via the urine and feces. Due to its short half-life, it takes multiple days to maintain the therapeutic effects. As the drug is eliminated from the body via the kidneys, it is important to consider dosage adjustments in renal-impaired patients.
Toxicity:
Usually, the drug is well-tolerated when used in optimal dosage as prescribed by the healthcare provider. However, it also has a few side effects like any other drug. The symptoms of drug toxicity are mentioned below:
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Severe hypertension can occur as the drug increases norepinephrine levels; it may cause a significant increase in blood pressure, leading to a hypertensive crisis.
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High levels of the drug can cause excessive narrowing of the blood vessels, which impairs the blood flow to the vital organs.
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Elevations in norepinephrine can lead to a faster heart rate.
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Excessive levels of the hormone may result in effects on the central nervous system.
Clinical Studies for Droxidopa:
The drug has been extensively studied in clinical trials to assess its safety and efficacy. Several clinical studies have demonstrated significant improvement in symptoms and increased blood pressure. Also, the drug shows long-term safety in patients with extended periods of treatment.
Drug Interactions:
Like other medications, Droxidops is capable of interacting with other drugs, potentially affecting the safety and effectiveness of both drugs. Some of the common drug interactions are mentioned below:
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MAO Inhibitors - It should not be combined with Droxidops as it can lead to life-threatening hypertensive crises.
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Antihypertensive Medications - Droxidopa may counter the effects of antihypertensives. Hence, careful monitoring is required if these drugs are used in combination.
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Dopamine Agonists - When both drugs are used in combination, they could have additive effects on blood pressure and cardiovascular functions.
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Antipsychotics - The drug may interact, resulting in altered blood pressure and cardiovascular functions.
Other Specifications:-
Droxidopa in Pregnant Women:
The drug has to be used carefully during pregnancy. There are not many studies supporting the hypothesis.
Droxidopa in Lactating Women:
When considering medications for breastfeeding mothers, it is better to assess the risks to the children as it could result in birth defects or congenital anomalies.
Droxidopa in Pediatric Patients:
The use of the drug in pediatric patients is not clearly established. The drug is yet to receive approval for use in pediatric patients.
Droxidopa in Geriatric Patients:
The use of the drug is known to be beneficial in elderly individuals with orthostatic hypotension. Elderly individuals are usually more susceptible to blood pressure regulations, so it is better to start the treatment with lower doses.
Droxidopa in Renal Impairment Patients:
The drug is excreted through the kidneys and may affect patients with renal impairment. Hence, dose alterations may be recommended. The drug may not be effectively removed from the body by dialysis, and hence, its accumulation could result in potential adverse effects.
Droxidopa in Hepatic Impairment Patients:
The use of the drug in hepatic impairment is yet to be studied. The drug undergoes primary metabolization in the liver. So, hepatic impairment could affect the clearance of the drug. As a result, caution should be taken while using the drug.
