Eligibility Criteria:
Inclusion Criteria
Concurrent Medication:
Allowed:
* Aspirin and acetaminophen.
* Nonsteroidal anti-inflammatory agents.
* Opiates.
* Pyridoxine (only if accompanied by isoniazid).
* ddI, ddC, d4T, and 3TC if on a stable dose.
* AZT.
* Cimetidine if on a stable dose.
NOTE:
* Per 3/16/95 amendment, Lactaid may be taken by lactose-intolerant patients for effects of lactose in placebo capsules.
Concurrent Treatment:
Allowed:
* Acupuncture.
Patients must have:
* Documented HIV infection.
* Painful peripheral neuropathy.
NOTE:
* Patients in ACTG blinded studies of dideoxynucleosides such as ddI, ddC, and d4T are encouraged to enroll in this study.
Prior Medication:
Allowed:
* Prior ddI, ddC, d4T, or 3TC, if on a stable dose for at least 8 weeks prior to study entry.
* Prior cimetidine if on a stable dose for at least 2 weeks prior to study entry.
Exclusion Criteria
Co-existing Condition:
Patients with the following symptoms or conditions are excluded:
* Diabetes mellitus.
* Neurological disease of sufficient severity to confound the evaluation of peripheral neuropathy, such as myelopathy without neuropathy. (NOTE: Patients with both myelopathy AND painful peripheral neuropathy are eligible.)
* Electrocardiogram (EKG) indicating malignant arrhythmia or cardiac conduction disturbances (such as second or third degree AV block, anterior hemi-block, or prolonged QT interval).
* Suicidal thoughts of sufficient severity to require treatment with antidepressant medication.
Concurrent Medication:
Excluded:
* Phenytoin or carbamazepine (unless on stable dose for 8 weeks prior to study entry).
* Capsaicin.
* Any MAO inhibitor antidepressants, any tricyclic or tetracyclic antidepressants, certain serotonin re-uptake inhibitors (fluoxetine, paroxetine, and venlafaxine), or mexiletine (except as dispensed for this study).
* Disopyramide.
* Procainamide.
* Quinidine.
* Tocainide.
* Flecainide acetate.
* Encainide.
* Lidocaine.
* Cisplatin.
* Vincristine.
* Chloramphenicol, disulfiram, ethionamide glutethimide, gold, hydralazine, iodoquinol, metronidazole, nitrofurantoin, or ribavirin (only in patients in whom the onset or clear worsening of painful peripheral neuropathy was attributed to previously taking these drugs).
* Any investigational drugs other than 3TC (except with permission of the protocol team).
* Terfenadine (if concurrent with ketoconazole).
Patients with the following prior conditions are excluded:
* Documented history of cardiac disease.
* History of allergy to, or intolerance of, tricyclic antidepressants, mexiletine, or benztropine.
Prior Medication:
Excluded:
* Prior disopyramide.
* Prior procainamide.
* Prior quinidine.
* Prior tocainide.
* Prior flecainide acetate.
* Prior encainide.
* Prior lidocaine.
* Cisplatin or vincristine within 8 weeks prior to study entry.
* Chloramphenicol, disulfiram, ethionamide glutethimide, gold, hydralazine, iodoquinol, metronidazole, nitrofurantoin, or ribavirin within 8 weeks prior to study entry (only in patients in whom the onset or clear worsening of painful peripheral neuropathy was attributed to taking these drugs).
* Any MAO inhibitor antidepressants, any tricyclic or tetracyclic antidepressants, certain serotonin re-uptake inhibitors (fluoxetine, paroxetine, and venlafaxine), or mexiletine, within 4 weeks prior to study entry.
* More than 50 percent change in the weekly dosage of any pain control medications within 2 weeks prior to study entry.
Per 3/16/95 amendment:
* ddI, ddC, d4T, or 3TC within 8 weeks prior to study entry ONLY IF dideoxynucleoside dosing was suspended or permanently discontinued.
Risk Behavior:
Excluded:
* Active drug or alcohol abuse.