Ivermectin Sigillata (Ivermectin)

Ivermectin is an anthelmintic that targets parasitic helminths and ectoparasites.

• Onchocerciasis: reduces microfilarial load and helps prevent ocular and skin disease progression.
• Strongyloidiasis: eliminates intestinal larvae and prevents hyperinfection syndrome.
• Scabies: eradicates Sarcoptes scabiei mites, relieving intense itching and skin lesions.
• Pediculosis: kills head lice and nits, controlling infestation.
• Other helminth infections: treats various nematode infections as indicated by clinical guidelines.

• Ivermectin binds selectively to glutamate‑gated chloride channels found in invertebrate nerve and muscle cells. This binding increases chloride ion influx, causing hyperpolarization of the cell membrane, which leads to paralysis and death of the parasite while having minimal effect on mammalian cells due to the absence of these channels in humans.

Ivermectin is generally well tolerated, but adverse reactions can occur.

Common Side Effects

• Nausea: mild to moderate upset stomach.
• Dizziness: transient light‑headedness.
• Diarrhea: loose stools during treatment.
• Abdominal pain: cramping or discomfort.
• Headache: mild to moderate.
• Pruritus: itching at the site of parasite death.

Serious or Rare Side Effects

• Severe skin reactions such as Stevens‑Johnson syndrome.
• Hepatotoxicity: elevated liver enzymes or jaundice.
• Neurologic toxicity: seizures, ataxia, or altered mental status.
• Anaphylaxis: acute allergic reaction with airway compromise.
• Vision disturbances: blurred vision or optic neuritis.
• Severe hypotension: marked drop in blood pressure.

Before prescribing Ivermectin, clinicians should consider several safety measures.

• Hypersensitivity: avoid use in patients with known allergy to ivermectin or excipients.
• Hepatic impairment: assess liver function; dose adjustment may be required in severe disease.
• Central nervous system disorders: use cautiously in patients with a history of seizures or neurodegenerative conditions.
• Concomitant CYP3A4 inhibitors: monitor for increased drug exposure when strong inhibitors are co‑administered.
• Pregnancy and breastfeeding: evaluate risk‑benefit ratio; limited data are available.
• Store at ambient temperature: keep in the original container, protect from moisture and light.

Ivermectin may interact with other medicines, requiring attention to avoid adverse outcomes.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): may markedly increase ivermectin plasma concentrations.
• P‑glycoprotein inhibitors (e.g., verapamil, quinidine): can raise systemic exposure and risk of neurotoxicity.

Moderate Interactions (Monitor Closely)

• Warfarin: may potentiate anticoagulant effect; monitor INR.
• Other antiparasitics (e.g., benzimidazoles): may increase gastrointestinal irritation.
• Immunosuppressants: monitor for altered infection risk or drug levels.