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Phenylephrine Hydrochloride/GuaifenesinPronouncation: (Fen-ill-EFF-rin HIGH-droe-KLOR-ide /GWHY-fen-ah-sin)
Class: Decongestant, Expectorant
- Liquid 5 mg phenylephrine hydrochloride and 100 mg guaifenesin
- Liquid 7.5 mg phenylephrine hydrochloride and 100 mg guaifenesin
- Capsules 7.5 mg phenylephrine hydrochloride and 200 mg guaifenesin
- Capsules, extended-release 10 mg phenylephrine hydrochloride and 300 mg guaifenesin
- Capsules 15 mg phenylephrine hydrochloride and 400 mg guaifenesin
- Tablets 15 mg phenylephrine hydrochloride and 600 mg guaifenesin
GFN 600/Phenylephrine 20
- Tablets 20 mg phenylephrine hydrochloride and 600 mg guaifenesin
- Tablets, extended-release 20 mg phenylephrine hydrochloride and 315 mg guaifenesin
- Capsules, extended-release 30 mg phenylephrine hydrochloride and 600 mg guaifenesin
- Tablets, extended-release 40 mg phenylephrine hydrochloride and 650 mg guaifenesin
- Tablets, extended-release 40 mg phenylephrine hydrochloride and 1,200 mg guaifenesin
Mechanism of Action
Stimulates postsynaptic alpha-receptors, resulting in vasoconstriction, which reduces congestion.Guaifenesin
May enhance output of respiratory tract fluid by reducing adhesiveness and surface tension, enhancing removal of viscous mucus and making nonproductive coughs more productive and less frequent.
Indications and Usage
Temporary relief of symptoms of upper respiratory tract disorders such as sinusitis, vasomotor rhinitis, and hay fever; temporary relief of coughs associated with respiratory tract infections and related conditions such as sinusitis, pharyngitis, bronchitis, and asthma when tenacious mucus and/or mucus plugs and congestion complicate these conditions.
Hypersensitivity to any component of product; hypersensitivity or idiosyncrasy to sympathomimetic amines, which may manifest by insomnia, dizziness, weakness, tremor, or arrhythmias. Phenylephrine is contraindicated in patients with hypertension or ventricular tachycardia and should be employed only with extreme caution in elderly patients or in patients with hyperthyroidism, bradycardia, partial heart block, myocardial disease, or severe arteriosclerosis. Phenylephrine is contraindicated in patents on monoamine oxidase (MAO) inhibitor therapy and for 14 days after stopping MAO therapy (see Interactions section).
Dosage and AdministrationAdults and Children (12 yr and older) Rescon-GG Liquid
PO 10 mL q 4 to 6 hr (up to 40 mL/day).Entex Liquid
PO 5 to 10 mL q 4 to 6 hr (up to 40 mL/day).Guaifed-PD Capsules
PO 1 to 2 q 12 hr.Entex ER Capsules
PO 1 or 2 q 12 hr.Guaifed Capsules
PO 1 q 12 hr.SINUvent PE Tablets
PO 2 q 12 hr.GFN 600/Phenylephrine 20 Tablets
PO 1 or 2 q 12 hr (up to 2/day).Liquibid-PD Tablets
PO 1 or 2 q 12 hr (up to 4/day).Liquibid-D Tablets
PO 1 q 12 hr.Liquibid-D 1200 Tablets
PO 1 q 12 hr.Children (6 to 12 yr)
PO ½ tablet q 12 hr (max, 1 tablets in 24 hr).
- Give with food if GI upset occurs.
- Tablets may be broken in half for ease of administration. Do not crush or chew tablets or half-tablets.
Store tablets at controlled room temperature (59° to 86°F).
Drug InteractionsBeta-adrenergic blockers, MAO inhibitors
May potentiate the pressor effect of phenylephrine.Digitalis glycosides, other vasopressor drugs during halothane anesthesia
The risk of cardiac arrhythmias may be increased.Guanethidine, mecamylamine, methyldopa, reserpine, veratrum alkaloids
Hypotensive effects of these agents may be reduced.Tricyclic antidepressants
Effects of phenylephrine may be decreased.
Laboratory Test Interactions
Guaifenesin may interfere with the interpretation of the test for urinary 5-hydroxyindoleacetic acid for the diagnosis of carcinoid syndrome; VMA test for catecholamines may be falsely elevated; guaifenesin may increase renal clearance for urate and thereby lower serum uric acid levels.
Tachycardia; palpitations; arrhythmias; cardiovascular collapse with hypotension.
Headache; dizziness; fear; anxiety; nervousness; restlessness; tremor; weakness; insomnia; hallucinations; convulsions; CNS depression.
Category C .
Small amounts of phenylephrine excreted in breast milk.
Not recommended for use in children under 6 yr.
Patients 60 yr and older are more likely to experience adverse sympathomimetic effects.
Special Risk Patients
Use with caution in patients with hypertension, heart disease, asthma, hyperthyroidism, increased intraocular pressure, diabetes mellitus, prostatic hypertrophy.
Has abuse potential.
Cardiac arrhythmias, cerebral hemorrhage, pulmonary edema, palpitation, tremor, dizziness, vomiting, fear, labored breathing, headache, dryness of mouth, pallor, weakness, panic, anxiety, confusion, hallucinations, delirium.
- Explain name, dose, action, and potential side effects of drug.
- Advise patient how to properly take medication.
- Advise patient that tablets may be broken in half for ease of administration.
- Instruct patient to not chew or crush tablets or half-tablets and to swallow whole.
- Advise patient to take with food if GI upset occurs.
- Advise patient that if a dose is missed to take as soon as remembered unless it is nearing time for the next dose. Caution patient to not double the dose to catch up.
- Instruct patient to discontinue use and report any of the following symptoms to health care provider: nervousness, dizziness, sleeplessness; persistent or recurrent cough; cough associated with fever, rash, or persistent headache; bothersome side effects.
- Advise patient that if symptoms are not controlled, not to increase the dose of medication but to inform health care provider.
- Advise women to notify health care provider if pregnant, planning to become pregnant, or breastfeeding.
- Caution patient to not take any prescription or OTC medications, or dietary supplements unless advised by health care provider.
- Caution patient not to take MAO inhibitor while taking this medication.