Overview :
Eye infections caused by bacteria can be treated with the antibiotic eye solution, which contains both Polymyxin B sulfate and Trimethoprim. Before using this medication, it is important to read up on its potential side effects, drug interactions, pregnancy safety, dose, and storage options. Polymyxin B sulfate or Trimethoprim was authorized by the FDA in October 1988.
How Does Polymyxin B Sulfate and Trimethoprim Ophthalmic Solution Work?
Polymyxin B kills the bacteria, and Trimethoprim stops bacteria from growing, which is how this combination works. This medicine is only used to treat eye infections caused by bacteria. It will not help with any other kind of eye infection. Polymyxin B sticks to the phospholipids in the cell membrane of gram-negative bacteria. This binding destroys bacterial membranes in a way that is similar to how surface detergents work. It also makes the cell membrane more permeable, which means that metabolites that bacteria need to live are lost.
What Are the Uses of Polymyxin B Sulfate and Trimethoprim Ophthalmic Solution?
This drug is used to treat bacterial infections of the eyes (such as blepharitis and conjunctivitis). It has two antibiotics in it. Polymyxin B functions by destroying germs. Trimethoprim works by inhibiting bacterial growth. This drug is solely used to treat bacterial eye infections. It is ineffective against other types of eye infections. Every antibiotic's effectiveness can be reduced if it is used or misused unnecessarily.
Dosage:
This medication's dosage will vary depending on the patient. Follow the doctor's advice or the label's instructions. This information only reflects the average doses of this medication. If the dose differs, do not modify it unless the doctor instructs to do so. In addition to the drug's strength, the exact medical condition being treated will also dictate parameters such as how often the drug should be taken, how long each dose should be, and how long the treatment should last.
For Eye Infections:
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Adults and Children Two Months of Age and Older: Use one drop every three hours in the afflicted eye(s) for seven to ten days. For severe infections, the doctor may advise using the drops more frequently.
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Children Under the Age of Two Months: Use and dosage must be determined by the doctor.
Warning:
Although it is uncommon, some people may experience severe and occasionally fatal side effects when taking this medicine. Inform the doctor or get medical attention right away if any individual sees any of the following signs or symptoms that could indicate severe side effects:
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Rashes.
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Hives.
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Itching.
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Red, swollen, blistered, or peeling skin with or without fever.
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Wheezing.
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Chest or throat tightness.
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Difficulty breathing, swallowing, or talking.
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Unusual hoarseness of voice.
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Swelling of the mouth, face, lips, tongue, or throat.
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Changes in vision, eye pain, or significant eye irritation and swelling of the eyelids are all possible.
For Patients
What Are the Essential Facts One Should Be Aware of Regarding Bacterial Eye Infections?
Trauma, eye surgery, contact lens wear, immunological weaknesses, or other illnesses that promote bacterial growth can all cause bacterial eye infections. Conjunctivitis, sometimes known as pink eye, and blepharitis, a persistent inflammation of the eyelids, are the two most frequent bacterial infections of the eye.
The whites of the eyes turn red due to inflammation in bacterial conjunctivitis. Additionally, a burning sensation and the presence of yellow discharge or pus may occur, which can harden the eyelids and eyelashes overnight, causing difficulty in opening the eyes in the morning. It is worth noting that there exist other forms of conjunctivitis, but only bacterial conjunctivitis can be effectively treated with antibiotics.
Why Is This Drug Prescribed?
Polymyxin B and Trimethoprim eye drops are used to treat bacterial eye infections like conjunctivitis (also called "pinkeye"), which affects the membrane that covers the outside of the eyeball and the inside of the eyelid, and blepharoconjunctivitis, which affects both the outside of the eye and the eyelids. Antibiotics are the group of drugs that Polymyxin B and Trimethoprim are a part of. In order for them to work, they have to kill the germs that are causing the infection.
How Should This Medicine Be Used?
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The combination of Polymyxin B and Trimethoprim is provided as a solution (liquid) for intraocular induction.
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In general, instill this medicine into the affected eye every three hours (up to six times in 24 hours) for seven to ten days. Use Polymyxin B and Trimethoprim ophthalmic at approximately the same time each day. Follow the directions on the prescription label carefully and ask the doctor or pharmacist to explain anything that is not understandable. Use Polymyxin B and Trimethoprim ophthalmic as directed. Do not use more or less or more than prescribed by the doctor.
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After using Polymyxin B and Trimethoprim eye drops, it is important to avoid contact between the bottle's tip and the eyes, fingers, face, or any other surfaces. Contact with other surfaces can introduce bacteria into the eye drops. If there is a concern about contamination of the eye drops, it is advisable to seek guidance from a doctor or pharmacist.
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One should expect that their symptoms will improve during treatment. If the symptoms do not go away, get worse, or develop other eye problems during treatment, call the doctor immediately.
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Use Polymyxin B and Trimethoprim ophthalmic until the end of the prescription, even if it feels better.
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If the individuals stop using Polymyxin B and Trimethoprim ophthalmic right away, the infection may not be completely cured, and the bacteria may become resistant to the antibiotics.
To use eye drops, follow the steps below:
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Wash the hands thoroughly with soap and water.
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Tilt the head back and pull down the lower eyelid with the index finger to create a pocket.
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Hold the dropper (tip down) in the other hand. Place the remaining fingers of that hand in front of the face.
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While looking up, gently squeeze the dropper so that a drop falls into the pocket created by the lower eyelid.
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Remove the index finger from the lower eyelid.
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Close one’s eyes and tilt one’s head down as if looking at the floor.
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Place a finger on the tear duct and apply gentle pressure for two to three minutes.
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Replace and tighten the cap on the dropper bottle. Do not wipe or rinse the dropper tip.
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Wash the hands and, if necessary, the child's hands to remove any medication.
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Ask the pharmacist or doctor for a copy of the manufacturer's information for the patient.
What Special Precautions Should the Patient Take?
Before using Polymyxin B and ophthalmic Trimethoprim, Inform the doctor and pharmacist if the patient is allergic to Polymyxin B, Trimethoprim, any other medications, or any of the ingredients in Polymyxin B and Trimethoprim eye drops. Ask the pharmacist for a list of ingredients. Inform the doctor and pharmacist about other prescription and over-the-counter medicines, vitamins, dietary supplements, and herbal products that the patient is currently using or plans to take. They may need to be closely monitored for side effects.
Please consult the doctor if the patient has or has ever had any medical conditions. If the patient is pregnant, planning to become pregnant, or breastfeeding, consult the doctor. Inform the doctor if one becomes pregnant while using Polymyxin B and Trimethoprim ophthalmic solution.
Let the doctor know if the patient is using contact lenses. Do not wear contact lenses while having symptoms of bacterial conjunctivitis or when using eye drops for treatment. One should know that bacterial conjunctivitis spreads easily. Wash hands frequently, especially after touching the eyes. Once the infection subsides, one should wash or replace any eye makeup, contact lenses, or other items that came into contact with the infected eye.
For Doctors:
Drug Description:
Polymyxin B sulfate and Trimethoprim ophthalmic solution, USP, is a sterile antimicrobial ophthalmic solution. Polymyxin B sulfate is the sulfate salt of polymyxins B1 and B2 generated by Bacillus polymyxa (Prazmowski) Migula growth (Fam. Bacillaceae). On an anhydrous basis, it has a potency of at least 6,000 Polymyxin B units per milligram.
Ingredients:
Polymyxin B sulfate at 10,000 units/mL and Trimethoprim sulfate at 1 mg/mL as active components, and 0.04 mg/mL Benzalkonium chloride as a preservative. Inactive ingredients include purified water, sodium chloride, and sulfuric acid. Sodium hydroxide may also be present to modify the pH. It has a pH range of 4.0 to 6.2 and an osmolality range of 270 to 310 mOsm/kg.
Pharmacology in Clinical Application:
Trimethoprim is a synthetic antibacterial agent that is effective against both aerobic gram-positive and gram-negative ophthalmic infections. Trimethoprim inhibits the enzyme dihydrofolate reductase, which is responsible for the formation of tetrahydrofolic acid from dihydrofolic acid. As this binding is stronger for the bacterial enzyme than for the analogous mammalian enzyme, it primarily interferes with bacterial nucleic acid and protein manufacturing.
Polymyxin B, a cyclic lipopeptide antibiotic, is bactericidal against a wide range of gram-negative bacteria, most notably Pseudomonas aeruginosa. It improves the permeability of the bacterial cell membrane by interacting with the membrane's phospholipid components.
Blood samples were collected from 11 human volunteers for 20 minutes, one hour, and three hours after instilling two drops of an ophthalmic solution containing 1 mg of Trimethoprim and 10,000 units of Polymyxin B per mL in the eye. Peak serum concentrations of Trimethoprim were around 0.03g/mL and 1 unit/mL Polymyxin B.
In vitro investigations have shown that the anti-infective components of Polymyxin B sulfate and Trimethoprim ophthalmic solution, USP are active against the following bacterial pathogens that can cause external eye infections:
Trimethoprim: Staphylococcus aureus and Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus faecalis, Streptococcus pneumoniae, Haemophilus influenzae, Haemophilus aegyptius, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis (indole-negative), Proteus vulgaris (indole-positive), Enterobacter aerogenes and Serratia marcescens. Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, and Haemophilus influenzae are all susceptible to Polymyxin B.
Indications and Applications:
Polymyxin B sulfate and Trimethoprim ophthalmic solution, USP is indicated for the treatment of surface ocular bacterial infections caused by susceptible strains of the following bacteria: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Streptococcus viridans, Haemophilus influenzae, and Pseudomonas aeruginosa.
Contraindications:
Polymyxin B sulfate and Trimethoprim ophthalmic solution, USP, is not recommended for patients who are allergic to any of its components.
Administration and Dose:
In mild to moderate infections, apply one drop to the afflicted eye(s) every three hours (up to six doses per day) for seven to ten days. Polymyxin B sulfate and Trimethoprim ophthalmic solution, USP, is delivered sterile in opaque white low-density polyethylene ophthalmic dispenser bottles and tips with white high-impact polystyrene (HIPS).
Storage: Should be stored at 15° - 25°C (59° - 77°F) and kept away from light.
Warning: Do not inject. In case of a hypersensitive reaction to Polymyxin B sulfate and Trimethoprim ophthalmic solution, USP, stop using it. Polymyxin B sulfate and Trimethoprim ophthalmic solution, USP, is not recommended for the prevention or treatment of neonatal ophthalmia.
Carcinogenesis, Mutagenesis, and Fertility Impairment:
Carcinogenesis: Polymyxin B sulfate and Trimethoprim have not been subjected to long-term animal trials to assess carcinogenic risk. Trimethoprim has been shown in the Ames assay to be non-mutagenic. In studies at two laboratories, no chromosomal damage was detected in cultured Chinese hamster ovary cells at concentrations approximately 500 times human plasma levels after oral administration; at one of the laboratories, a low level of chromosomal damage was induced in these same cells at concentrations approximately 1,000 times human plasma levels after oral administration. There have been no studies on the mutagenic potential of Polymyxin B sulfate.
Reproductive Impairment: Polymyxin B sulfate has been shown to reduce horse sperm motility, but its effects on male or female fertility are unknown. Trimethoprim was administered to rats in oral doses as high as 70 mg/kg/day for males and 14 mg/kg/day for females, with no detrimental effects on fertility or general reproductive performance.
Teratogenic Consequences During Pregnancy: Pregnancy type C. Polymyxin B sulfate has not been studied in animal reproduction. It is unknown whether Polymyxin B sulfate can cause fetal damage or alter reproductive capacity when provided to a pregnant woman. Trimethoprim has been demonstrated to be teratogenic in rats when administered orally at 40 times the human dose. In certain rabbit investigations, oral doses six times the human therapeutic level was related to an increase in fetal loss (dead, resorbed, and deformed conceptuses).
Limited data exist on the use of Trimethoprim in pregnant women, with some studies reporting its effects in combination with Sulfamethoxazole. A retrospective study involving 186 pregnancies examined the outcomes of mothers who received either a placebo or oral Trimethoprim combined with Sulfamethoxazole. The incidence of congenital anomalies was found to be 4.5 percent in the placebo group (three out of 66) and 3.3 percent in the Trimethoprim and Sulfamethoxazole group (four out of 120). Interestingly, among the ten children whose mothers took the medication during the first trimester, no abnormalities were observed. Another study involving 35 children whose mothers had taken oral Trimethoprim and Sulfamethoxazole before or immediately after pregnancy revealed no congenital abnormalities. Trimethoprim should be taken during pregnancy only if the potential benefit outweighs the potential danger to the fetus since it may interfere with folic acid metabolism.
Nonteratogenic Effects: Oral treatment of Trimethoprim to rats at a dose of 70 mg/kg/day beginning in the third trimester and continuing through parturition and breastfeeding had no adverse effects on gestation or pup development and survival.
Nursing Mothers: It is unknown if this medication is excreted in human milk. As many medicines are excreted in human milk, a nursing woman should exercise caution when receiving Polymyxin B sulfate and Trimethoprim ophthalmic solution, USP.
Pediatric Use: The safety and effectiveness of this medication in children under the age of two months have not been demonstrated.
Geriatric Use: There have been no overall variations in safety or effectiveness between old and other adult patients.
Adverse Reactions:
Local irritation characterized by increased redness, burning, stinging, and/or itching is the most common adverse effect of Polymyxin B sulfate and Trimethoprim ophthalmic solution, USP. This can happen right after installation, within 48 hours, or at any moment with long-term use. There have also been numerous instances of hypersensitive reactions such as lid edema, itching, increased redness, tears, and/or circumocular dermatitis. Photosensitivity has been found in Trimethoprim-treated patients.
