Over-the-Counter Medications and APIs Review

A complete guide to active pharmaceutical ingredients (APIs), mechanisms of action, and clinical indications for common over-the-counter cold, flu, allergy, and cough treatments.

Paracetamol (Analgesic/Antipyretic)

An API found in doses of $500\,mg$ or $1000\,mg$ that works centrally to relieve pain (analgesic) and lower body temperature (antipyretic).

Phenylephrine

A weak oral decongestant that functions through vasoconstriction to treat mild blocked noses and congestion, often paired with Paracetamol in cold and flu bundles.

Diphenhydramine (in Benylin Chesty Coughs Original)

A sedating antihistamine that acts as an anti-inflammatory and allergy symptom blocker; it causes drowsiness and is used for nighttime productive coughs.

Ammonium chloride

An expectorant that loosens and increases mucus to make it easier for the patient to cough up phlegm.

Guaifenesin

An expectorant (mucolytic) that thins and loosens thick mucus to relieve productive chesty coughs in adults and children over $12$.

Glycerol (Demulcent)

A demulcent syrup that coats and soothes an irritated throat, typically used for mild tickly dry coughs or throat irritation.

Bronchostop Herbal API

A combination of ivy leaf, plantain, and marshmallow that acts as a dual-action expectorant for both productive and dry coughs.

Loratadine (Clarityn)

A non-sedating $10\,mg$ H1 receptor blocker used for daytime relief of hay fever and allergic rhinitis symptoms like runny nose and sneezing.

Chlorphenamine (Piriton)

A sedating H1 antagonist that blocks and dries nasal mucus secretions, recommended for acute allergies or nighttime cold symptoms.

Dextromethorphan

A non-opioid central cough reflex suppressant (antitussive) used to treat persistent, non-productive dry coughs.

Ibuprofen

An NSAID (Non-Steroidal Anti-Inflammatory Drug) available in $200\,mg$ or $400\,mg$ that provides anti-inflammatory, analgesic, and mild antipyretic effects.

Menthol & Eucalyptus inhalation

A steam vapour decongestant and soothing agent used for nasal/chest relief, which may trigger asthma by tightening airway muscles.

Olbas oil

A blend of essential oils (including menthol and eucalyptus) with vapour decongestant and antibacterial properties used for stuffy noses and phlegm build-up.

Xylometazoline (0.1% Nasal Spray)

A topical alpha-agonist vasoconstrictor used for instant relief of severe nasal block; carrying a risk of rebound congestion if used for more than $5$ days.

Citric acid monohydrate (Simple Linctus)

A mild demulcent sugar syrup that coats the throat and stimulates saliva production to soothe simple dry coughs in adults.

Flurbiprofen (Strepsils lozenge)

A local NSAID lozenge ($8.75\,mg$) used to treat acute sore throat pain through local anti-inflammatory action.

Pseudoephedrine (Sudafed tablets)

A systemic alpha-agonist decongestant that causes vasoconstriction and bronchodilation to treat moderate ongoing nasal congestion.

Phenol 0.5% (Ultrachloraseptic)

A local anaesthetic and antiseptic throat spray used to treat pain and bacterial infection in the throat.