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A-Spas S/L Side Effects

Generic name: hyoscyamine

Medically reviewed by Last updated on Jun 10, 2024.

Note: This document contains side effect information about hyoscyamine. Some dosage forms listed on this page may not apply to the brand name A-Spas S/L.

Applies to hyoscyamine: oral conventional tablets and sublingual tablets, oral extended-release capsules and tablets, oral oral solution and elixir, oral orally disintegrating tablets, parenteral injection.

Side effects include:

Most adverse effects are manifestations of pharmacologic effects at muscarinic-cholinergic receptors and usually are reversible when therapy is discontinued.

Severity and frequency of adverse effects are dose related and individual intolerance varies greatly; adverse effects occasionally may be obviated by a reduction in dosage but this also may eliminate potential therapeutic effects.

Adverse effects include dry mouth, urinary hesitancy and retention, blurred vision, tachycardia, palpitations, mydriasis, increased ocular tension, loss of taste, headache, nervousness, drowsiness, weakness, fatigue, dizziness, insomnia, nausea, vomiting, impotence, constipation, bloated feeling, abdominal pain, diarrhea, allergic reactions or drug idiosyncrasies, urticaria and other dermal manifestations, ataxia, speech disturbance, mental confusion and/or excitement (especially in geriatric patients), short-term memory loss, hallucinations, and decreased sweating.

For Healthcare Professionals

Applies to hyoscyamine: compounding powder, injectable solution, oral capsule extended release, oral liquid, oral solution, oral spray, oral tablet, oral tablet chewable, oral tablet disintegrating, oral tablet extended release, sublingual tablet.


Frequency not reported: Palpitations, tachycardia[Ref]


Frequency not reported: Abdominal pain, bloated feeling, constipation, diarrhea, dryness of the mouth, nausea, vomiting[Ref]


Frequency not reported: Impotence, lactation suppression, urinary hesitancy and retention[Ref]


Frequency not reported: Allergic reactions or drug idiosyncrasies[Ref]

Nervous system

Frequency not reported: Ataxia, dizziness, drowsiness, headache, loss of taste, short-term memory loss, some degree of mental confusion and/or excitement (especially in elderly persons), speech disturbance[Ref]


Frequency not reported: Blurred vision, cycloplegia, increased ocular tension, mydriasis[Ref]


Frequency not reported: Hallucinations, insomnia, nervousness[Ref]


Frequency not reported: Fatigue, weakness[Ref]


Frequency not reported: Decreased sweating, other dermal manifestations, urticaria[Ref]


1. (2008) "Product Information. Symax Duotab (hyoscyamine)." Capellon Pharmaceuticals

2. (2018) "Product Information. Anaspaz (hyoscyamine)." Ascher, B.F. and Company Inc

3. (2018) "Product Information. Levbid (hyoscyamine)." Alaven Pharmaceuticals

4. (2018) "Product Information. Levsin SL (hyoscyamine)." Alaven Pharmaceuticals

5. (2018) "Product Information. NuLev (hyoscyamine)." Alaven Pharmaceuticals

6. (2018) "Product Information. Oscimin (hyoscyamine)." Larken Laboratories Inc

7. (2018) "Product Information. Symax SL (hyoscyamine)." Capellon Pharmaceuticals

8. (2018) "Product Information. Symax SR (hyoscyamine)." Capellon Pharmaceuticals

9. (2018) "Product Information. Hyosyne (hyoscyamine)." Silarx Pharmaceuticals Inc

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.