Histadec Side Effects
Generic name: chlorpheniramine / phenylephrine
Medically reviewed by Drugs.com. Last updated on May 13, 2022.
Note: This document contains side effect information about chlorpheniramine / phenylephrine. Some dosage forms listed on this page may not apply to the brand name Histadec.
Applies to chlorpheniramine / phenylephrine: oral tablet.
Serious side effects of Histadec
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
Other side effects of Histadec
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Feeling nervous and excitable.
- Not able to sleep.
- Feeling sleepy.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.
For Healthcare Professionals
Applies to chlorpheniramine/phenylephrine: oral capsule extended release, oral drops, oral elixir, oral liquid, oral suspension, oral suspension extended release, oral syrup, oral tablet, oral tablet chewable, oral tablet extended release.
Frequency not reported: Fatigue (chlorpheniramine)[Ref]
More about Histadec (chlorpheniramine / phenylephrine)
Related treatment guides
1. Sur DK, Plesa ML "Treatment of allergic rhinitis." Am Fam Physician 92 (2015): 985-92
2. "PDR Generics." Montvale, NJ: Medical Economics (1998):
Some side effects may not be reported. You may report them to the FDA.