Can it raise blood pressure?

Yes. Blood-vessel constriction can raise blood pressure, which can be therapeutic during anaesthetic hypotension but harmful in susceptible people.

Can I drive after eye drops?

Wait until blurred vision has completely cleared before driving or operating machinery.

Can children or older people use it?

Restrictions are formulation-specific. Selected high-strength eye drops are contraindicated below 12 years and in older people, while safety of selected injections has not been established in children.

phenylephrine hydrochloride

phenylephrine hydrochloride at a glance

Medicine class

Direct-acting sympathomimetic that predominantly stimulates alpha-adrenoceptors.

Flamingo Max Strength Congestion Relief 12.2 mg capsules, hard — Current selected SmPC Phenylephrine 0.1 mg/ml, solution for injection — Current selected SmPC

Available forms

Selected products include oral capsules, single-use eye drops, ready-to-use injection and concentrated injection requiring dilution.

Flamingo Max Strength Congestion Relief 12.2 mg capsules, hard — Current selected SmPC Phenylephrine 0.1 mg/ml, solution for injection — Current selected SmPC

What is phenylephrine hydrochloride used for?

Selected products have different licensed uses:

Oral capsules: relief of nasal congestion, particularly with colds, influenza or hay fever.

Eye drops: pupil dilation during diagnostic or therapeutic eye procedures.

Injection: treatment of low blood pressure during spinal, epidural or general anaesthesia.

Flamingo Max Strength Congestion Relief 12.2 mg capsules, hard — Current selected SmPC Phenylephrine 0.1 mg/ml, solution for injection — Current selected SmPC Minims Phenylephrine Hydrochloride 10% w/v, Eye drops solution — Current selected SmPC Phenylephrine Injection BP 10 mg/ml — Current selected SmPC

Mechanism, explained

How does phenylephrine hydrochloride work?

Phenylephrine mainly stimulates alpha-1 adrenoceptors, tightening blood vessels. This reduces nasal swelling; systemically it increases vascular resistance and blood pressure. In the eye, it enlarges the pupil with little effect on focusing.

phenylephrine hydrochloride preparations and strengths

Eye drops

Route: Ophthalmic

Strengths: 2.5% w/v, 10% w/v

Minims Phenylephrine Hydrochloride 10% w/v, Eye drops solution — Current selected SmPC Minims Phenylephrine Hydrochloride 2.5% w/v, Eye drops solution — Current selected SmPC

Capsule

Route: Oral

Strengths: 12.2 mg

Flamingo Max Strength Congestion Relief 12.2 mg capsules, hard — Current selected SmPC

Injection

Route: Parenteral

Strengths: 50 micrograms/mL, 100 micrograms/mL, 0.1 mg/mL, 10 mg/mL

Phenylephrine 0.1 mg/ml, solution for injection — Current selected SmPC

How to take phenylephrine hydrochloride

How it is given depends on the formulation and reason for use.

Swallow oral capsules whole with water and follow the packet leaflet. Avoid another decongestant unless advised by a healthcare professional.

Eye drops are normally given for an examination or procedure. Gently press the inner corner of the eye during and after use to reduce systemic absorption, and discard a single-use unit after opening.

Injection is given intravenously by trained healthcare professionals. The concentrated product must be diluted, and the injection site checked for leakage.

phenylephrine hydrochloride side effects

Common or expected effects

Headache, nausea or vomiting.
Palpitations or changes in heart rate or blood pressure; injection can commonly cause reflex slowing of the heart.
With eye drops: stinging, irritation, light sensitivity or temporary blurred vision.

Get urgent medical advice

Severe high blood pressure, chest pain, myocardial ischaemia or dangerous heart rhythm.
Breathing difficulty or pulmonary oedema.
Acute worsening of angle-closure glaucoma.
Severe hypersensitivity reaction.
Tissue ischaemia or necrosis if injection leaks outside a vein.

phenylephrine hydrochloride in pregnancy

Oral decongestant phenylephrine should generally be avoided during pregnancy because vasoconstriction may reduce placental blood flow. Selected eye drops should be used only when a physician considers them essential. Advice for injectable products differs: one selected injection permits use when clinically indicated, while the selected concentrate is not recommended during pregnancy.

phenylephrine hydrochloride interactions

Interactions vary by formulation and can cause excessive vasoconstriction, high blood pressure or abnormal heart rhythms.

Monoamine oxidase inhibitors

Concurrent or recent use can cause severe hypertension and hyperthermia; restrictions differ between products.

Tricyclic antidepressants

Common questions about phenylephrine hydrochloride

Answers are fully visible for fast scanning and source review.

Are capsules, eye drops and injections interchangeable?

No. They have different routes, uses, restrictions and handling requirements.

Sources

These sources were used to prepare and review this medicine page.

Flamingo Max Strength Congestion Relief 12.2 mg capsules, hard — Current selected SmPCSummary of Product Characteristics · emc

Phenylephrine 0.1 mg/ml, solution for injection — Current selected SmPCSummary of Product Characteristics · emc

Minims Phenylephrine Hydrochloride 10% w/v, Eye drops solution — Current selected SmPCSummary of Product Characteristics · emc

Phenylephrine Injection BP 10 mg/ml — Current selected SmPCSummary of Product Characteristics · emc

Prepared and reviewed by the iatroX editorial team.