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SudoGest Side Effects

Generic name: pseudoephedrine

Medically reviewed by Last updated on Oct 25, 2022.

Note: This document contains side effect information about pseudoephedrine. Some dosage forms listed on this page may not apply to the brand name SudoGest.

Applies to pseudoephedrine: oral solution, oral tablets.

Side effects include:

Nervous system effects (e.g., CNS stimulation, nervousness, excitability, restlessness, dizziness, weakness, insomnia, headache, drowsiness) and cardiovascular effects (e.g., increased irritability of heart muscle, altered rhythmic function of ventricles, tachycardia, palpitation).

For Healthcare Professionals

Applies to pseudoephedrine: compounding powder, oral capsule, oral liquid, oral suspension extended release, oral tablet, oral tablet chewable, oral tablet extended release.


The most commonly reported adverse effects have included cardiovascular and (e.g. elevated blood pressure, tachycardia, or arrhythmias), CNS stimulation (e.g. restlessness, insomnia, anxiety, tremors, and rarely hallucinations), skin rashes, and urinary retention.[Ref]


Frequency not reported: Tachycardia, palpitations, arrhythmia, hypertension, impaired circulation to the extremities[Ref]

Nervous system

Frequency not reported: Headache, tremor


Frequency not reported: Dry mouth, nausea, vomiting


Frequency not reported: Hypersensitivity reactions including cross-sensitivity with other sympathomimetic[Ref]


Rare (less than 0.1%): Hallucinations

Frequency not reported: Restlessness, insomnia, sleep disturbances, anxiety, excitability[Ref]


Frequency not reported: Urinary retention, especially in men with prostatic enlargement


Frequency not reported: Angle-closure glaucoma


Frequency not reported: Skin rashes, fixed drug eruption in the form of erythematous nodular patches[Ref]


Post marketing reports: False-positive amphetamine immunoassay[Ref]

False-positives can occur far below the published threshold indicating that cross-reactivity in human specimens is sometimes greater than the limits reported.[Ref]

Frequently asked questions


1. Product Information. Sudafed (pseudoephedrine). Glaxo Wellcome. 2001.

2. Cerner Multum, Inc. UK Summary of Product Characteristics.

3. Cerner Multum, Inc. Australian Product Information.

4. Depriest AZ, Knight JL, Doering PL, Black DL. Pseudoephedrine and false-positive immunoassay urine drug tests for amphetamine. Pharmacotherapy. 2012.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.