paracetamol + phenylephrine hydrochloride: clinical use

Prescribing considerations

• Confirm nasal congestion is present and reconcile cold, flu and analgesic products to avoid duplicate exposure.
• Assess cardiovascular history, blood pressure, thyroid disease, diabetes, glaucoma, urinary outflow symptoms, Raynaud's phenomenon and interactions.
• Consider hepatic or renal impairment, alcohol-related liver risk, malnutrition, sepsis and glutathione depletion.
• Review excipients when sodium restriction, phenylketonuria, carbohydrate or lactose intolerance, or sulphite sensitivity is relevant.

Contraindications and cautions

• Hypersensitivity to either active ingredient or an excipient.
• Severe coronary heart disease or cardiovascular disorder, hypertension or hyperthyroidism.
• Diabetes mellitus, phaeochromocytoma, closed-angle glaucoma or prostatic enlargement.
• Current or recent monoamine oxidase inhibitor treatment.
• Concurrent use of another sympathomimetic decongestant.

Monitoring

• Review blood pressure and cardiovascular symptoms when clinically relevant.
• For prolonged regular paracetamol exposure with warfarin, consider the effect on anticoagulation.
• Suspected overdose requires urgent assessment even when early symptoms are absent.

Clinical pharmacology

Paracetamol has central analgesic and antipyretic effects. Phenylephrine is a postsynaptic alpha-1 adrenergic agonist that reduces nasal mucosal oedema through vasoconstriction; oral bioavailability is limited by first-pass metabolism.

Formulation and product differences

• Both selected products are powders for oral solution, but active-ingredient strengths differ and they should not be assumed interchangeable.
• Excipients differ, including sodium, sugars, lactose, aspartame and sulphites.