• diarrhea;

• confusion, hallucinations;

• unusual thoughts or behavior;

• fast, pounding, or uneven heart rate;

• rash or flushing; or

• eye pain.

Less serious side effects may include:

• dizziness, drowsiness, feeling nervous;

• blurred vision, headache;

• sleep problems (insomnia);

• nausea, vomiting, bloating, heartburn, or constipation;

• changes in taste;

• problems with urination;

• decreased sweating;

• dry mouth; or

• impotence, loss of interest in sex, or trouble having an orgasm.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

What other drugs will affect hyoscyamine?

Before taking this medication, tell your doctor if you are using any of the following drugs:

• amantadine (Symmetrel);

• haloperidol (Haldol);

• an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate);

• phenothiazines such as chlorpromazine (Thorazine), fluphenazine (Prolixin), mesoridazine (Serentil), perphenazine (Trilafon), prochlorperazine (Compazine), thioridazine (Mellaril), or trifluperazine (Stelazine); or

• antidepressants such as amitriptyline (Elavil, Etrafon), amoxapine (Ascendin), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Sinequan), imipramine (Janimine, Tofranil), nortriptyline (Pamelor), protriptyline (Vivactil), or trimipramine (Surmontil).

This list is not complete and there may be other drugs that can interact with hyoscyamine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Where can I get more information?

Your pharmacist can provide more information about hyoscyamine.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.