Inclusion Criteria

Concurrent Medication:

Allowed:

• Vitamin supplements.
• Zidovudine (AZT) for patients previously taking AZT. However, dosing with spiramycin should be delayed until the dose of AZT has stabilized. The dose may be decreased for AZT-associated toxicity.

Allowed for diarrhea:

• Loperamide hydrochloride capsules (2 mg) or loperamide hydrochloride liquid (1 mg/5 ml).

Allowed for nausea:

• Sucralfate and metoclopramide hydrochloride.

Allowed for vomiting:

• Prochlorperazine and trimethobenzamide hydrochloride.
• Allowed as prophylaxis for Pneumocystis carinii pneumonia (PCP):
• Aerosolized pentamidine.

Patients must have:

• A diagnosis of AIDS according to the CDC.
• Chronic diarrhea.
• Presence of Cryptosporidium oocysts in stool specimen. Patients or a legally authorized representative must sign an informed consent form. Diet will be lactose free, maximum 7 g fat/day with unlimited calorie intake. Patients who require total parenteral nutrition will also be allowed oral intake.

Exclusion Criteria

Co-existing Condition:

Patients with the following are excluded:

• Grade 4 (for hematologic) or Grade 3 (for all other) toxicity.
• Known sensitivity to macrolide antibiotics.
• Presence of other diarrhea-causing pathogens.
• Active opportunistic infection requiring systemic antimicrobial therapy.
• Toxicity grades according to NIAID toxicity scale for adults.

Concurrent Medication:

Excluded:

• Other investigational drugs.
• Cancer chemotherapy.
• Alpha interferon.
• Other immunomodulating agents.
• Other macrolide antibiotics.
• Trimethoprim / sulfamethoxazole.
• Ganciclovir.
• H2 blockers and AL-721.
• Medications known to cause gastrointestinal irritation or alteration of gastrointestinal motility or absorption should be avoided if possible.
• Zidovudine (AZT) therapy may not be initiated and the dose may not be increased during the study.

Patients with the following are excluded:

• Grade 4 (for hematologic) or Grade 3 (for all other) toxicity.
• Known sensitivity to macrolide antibiotics.
• Presence of other diarrhea-causing pathogens.
• Active opportunistic infection requiring systemic antimicrobial therapy.
• Toxicity grades according to NIAID toxicity scale for adults.

Prior Medication:

Excluded within 7 days of study entry:

• Investigational drugs.

Excluded within 14 days of study entry:

• Cancer chemotherapy.
• Alpha interferon.
• Other immunomodulating agents.
• Other macrolide antibiotics.
• Trimethoprim / sulfamethoxazole.
• Ganciclovir.