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warnings
WARNINGS Do not exceed recommended dosage. If nervousness, dizziness, or sleeplessness occur, discontinue use and consult a doctor. If symptoms do not improve within 7 days or are accompanied by a fever, consult a doctor. General Sympathomimetic amines should be used with caution in patients with hypertension, diabetes mellitus, ischemic heart disease, increased intraocular pressure, hyperthyroidism, or prostatic hypertrophy. Sympathomimetics may produce central nervous system stimulation with convulsions or cardiovascular collapse with accompanying hypotension. Hypertensive crisis can occur with concurrent use of phenylephrine and monoamine oxidase (MAO) inhibitors (or for 14 days after stopping MAOI therapy), indomethacin or with beta- blockers and methyldopa. If a hypertensive crisis occurs, these drugs should be discontinued immediately and therapy to lower blood pressure should be instituted. Fever should be managed by means of external cooling.
ADVERSE REACTIONS Sympathomimetic drugs have been associated with certain untoward reactions including fear, anxiety, tenseness, restlessness, tremor, weakness, pallor, respiratory difficulty, dysuria, insomnia, hallucinations, convulsions, CNS depression, arrhythmias, and cardiovascular collapse with hypotension. Mild central nervous system stimulation, especially in those patients who are hypersensitive to sympathomimetic drugs, may occur. Nervousness, excitability, restlessness, dizziness, weakness, and insomnia may also occur. Headache and drowsiness have also been reported. Large doses may cause light-headedness, nausea and/or vomiting. Patient idiosyncrasy to adrenergic agents may be manifested by insomnia, dizziness, weakness, tremor or arrhythmias. Guaifenesin is well tolerated and has a wide margin of safety. Side effects have been generally mild and infrequent. Nausea and vomiting are the side effects that occur most commonly. Dizziness, headache, and rash (including urticaria) have been reported rarely.