Usage
This combination medication is primarily prescribed for the temporary relief of minor eye symptoms like itching, redness, and irritation caused by allergies (e.g., allergic conjunctivitis, hay fever), environmental irritants (e.g., dust, smoke, wind, sun), or eye strain (e.g., computer vision syndrome). It is also used for the temporary relief of burning and tearing associated with these conditions.
Its pharmacological classifications include:
- Decongestant: Naphazoline and phenylephrine are vasoconstrictors that shrink swollen blood vessels in the conjunctiva, reducing redness and swelling.
- Anti-allergic: While this combination itself does not intrinsically contain an anti-allergic like some similar formulations, the decongestants provide relief from allergy symptoms.
- Counterirritant/Topical Anesthetic: Camphor and menthol create a cooling sensation that soothes irritation and discomfort.
Alternate Names
There is no single international non-proprietary name (INN) for this combination. It is often referred to by the names of its individual ingredients. Several brand names exist under which it’s marketed (e.g. Andre I-Kul, Ocurest, Briscool).
How It Works
Pharmacodynamics:
- Naphazoline and Phenylephrine: These are sympathomimetic amines acting as α-adrenergic agonists, causing vasoconstriction of the conjunctival blood vessels, thus reducing eye redness and swelling.
- Camphor and Menthol: These agents stimulate cold receptors, creating a cooling sensation which masks the discomfort of irritation and has a mild analgesic effect.
Pharmacokinetics:
- Absorption: The drugs are absorbed locally into the eye tissues after topical application. Systemic absorption is minimal, but can increase if the nasal mucosa is compromised or if excessively high doses are applied.
- Metabolism and Elimination: Information on the specific metabolic pathways of each component in ophthalmic form is limited. However, when systemically absorbed, naphazoline and phenylephrine are primarily metabolized in the liver. Camphor and menthol are extensively metabolized, mostly in the liver, and eliminated through the kidneys.
Dosage
Standard Dosage
Adults: Instill 1-2 drops in the affected eye(s) every 3-4 hours, or as directed by a physician.
Children: Use in children under 12 is generally not recommended unless under the specific direction of a physician.
Special Cases:
- Elderly Patients: Use with caution due to the potential for increased systemic absorption and cardiovascular side effects. Monitoring blood pressure and heart rate is advisable.
- Patients with Renal Impairment: Use cautiously. Monitor for systemic side effects.
- Patients with Hepatic Dysfunction: Use cautiously. Monitor for systemic side effects.
- Patients with Comorbid Conditions: Use with caution in patients with hypertension, diabetes, hyperthyroidism, cardiovascular disease, and benign prostatic hyperplasia (BPH), as phenylephrine can exacerbate these conditions. Patients with closed-angle glaucoma should not use this medication.
Clinical Use Cases
This combination drug is not typically employed in clinical scenarios such as intubation, surgical procedures, mechanical ventilation, or the ICU. Its use is primarily limited to outpatient management of minor eye irritation and allergies.
Dosage Adjustments
Dosage adjustments may be needed based on patient response and tolerability. Start with the lowest recommended dose and increase as needed. For patients with renal or hepatic impairment, close monitoring is crucial, and dosage reductions may be considered.
Side Effects
Common Side Effects
- Transient blurred vision
- Burning or stinging upon instillation
- Eye pain or irritation
- Increased sensitivity to light (photophobia)
- Watery eyes
- Mydriasis (pupil dilation) - particularly with prolonged use.
- Rebound congestion (worsening of symptoms) with prolonged or excessive use
Rare but Serious Side Effects
- Allergic reactions (e.g., rash, itching, swelling of the face, tongue, or throat, difficulty breathing)
- Systemic effects such as headache, dizziness, nervousness, tremor, or changes in heart rate or blood pressure (rare, but possible with increased systemic absorption)
- Acute angle-closure glaucoma (in predisposed individuals)
Long-Term Effects
Prolonged or excessive use can lead to rebound congestion (rhinitis medicamentosa) which is characterized by worsening nasal congestion. Long-term use can also result in dependence and tolerance to the decongestant effects.
Contraindications
- Absolute Contraindications: Narrow-angle glaucoma, concurrent use of monoamine oxidase inhibitors (MAOIs), hypersensitivity to any of the components.
- Relative Contraindications: Cardiovascular disease (e.g., hypertension, coronary artery disease), hyperthyroidism, diabetes, BPH, severe hepatic or renal impairment.
Drug Interactions
- MAOIs (e.g., selegiline, phenelzine) – can lead to severe hypertensive crisis.
- Beta-blockers (e.g., atenolol, propranolol) - can lead to paradoxical hypertension or reduced efficacy of beta-blockers.
- Tricyclic antidepressants – can potentiate the cardiovascular effects of phenylephrine.
- Other sympathomimetic drugs – can lead to additive effects and increase the risk of side effects.
Pregnancy and Breastfeeding
The safety of this combination during pregnancy and breastfeeding has not been definitively established. Phenylephrine is categorized as Pregnancy Category C, indicating a lack of adequate and well-controlled studies in humans. Naphazoline, camphor, and menthol also have limited safety data in pregnancy. Therefore, the use of this combination during pregnancy or while breastfeeding should be limited to cases where the potential benefits outweigh the risks. Consult a physician before use.
Drug Profile Summary
- Mechanism of Action: α-adrenergic agonists causing vasoconstriction (naphazoline, phenylephrine), counterirritants with mild analgesic effect (camphor, menthol).
- Side Effects: Blurred vision, burning/stinging, eye pain/irritation, photophobia, watery eyes, rebound congestion.
- Contraindications: Narrow-angle glaucoma, concurrent MAOI use, hypersensitivity.
- Drug Interactions: MAOIs, beta-blockers, tricyclic antidepressants, sympathomimetics.
- Pregnancy & Breastfeeding: Use with caution; consult a physician.
- Dosage: 1-2 drops in affected eye(s) every 3-4 hours.
- Monitoring Parameters: Eye pressure, heart rate, blood pressure (especially in elderly and those with comorbidities).
Popular Combinations
This combination itself represents a common formulation. The addition of an antihistamine like chlorpheniramine is seen in some products, which may offer enhanced allergy relief.
Precautions
Wash hands before and after use. Avoid touching the tip of the bottle to any surface. Remove contact lenses before instillation and wait at least 15 minutes before reinserting. Do not use if the solution changes color or becomes cloudy. Inform patients about the potential for rebound congestion with prolonged use.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Camphor + Menthol + Naphazoline + Phenylephrine?
A: 1-2 drops in the affected eye(s) every 3-4 hours as needed. Do not exceed recommended dosage.
A: No. Remove contact lenses before use and wait at least 15 minutes before reinserting.
Q3: Can pregnant or breastfeeding women use this?
A: Consult a physician. Safety in pregnancy and breastfeeding is not fully established. Use only if clearly needed and the potential benefits outweigh the risks.
Q4: Are there any serious side effects I should be aware of?
A: Although rare, allergic reactions and systemic effects like headache, dizziness, and changes in heart rate or blood pressure are possible. Notify a physician immediately if these occur. Prolonged use can also lead to rebound congestion.
Q5: How long can I use this medication?
A: Use only for the recommended duration (typically no more than 3-4 days unless advised by a physician) to avoid rebound congestion.
Q6: Can I use this with other eye drops?
A: If using other ophthalmic medications, wait at least 5 minutes between instillations.
Q7: What should I do if I miss a dose?
A: Instill the missed dose as soon as remembered, unless it is almost time for the next scheduled dose. Do not double the dose.
Q8: Can children use this eye drop?
A: Generally not recommended for children under 12 years of age unless specifically prescribed by a physician.
Q9: What are the signs of an allergic reaction to this medication?
A: Signs of an allergic reaction can include rash, itching, swelling (particularly of the face, tongue, or throat), and difficulty breathing. Seek immediate medical attention if these symptoms develop.
