Ivermectine Viatris (Ivermectin)

Ivermectin is an antiparasitic agent used to treat several helminthic and ectoparasitic infections.

• Onchocerciasis: reduces microfilarial load and helps prevent disease progression.
• Strongyloidiasis: eradicates intestinal Strongyloides stercoralis infection.
• Lymphatic filariasis (in combination therapy): contributes to the elimination of Wuchereria bancrofti microfilariae.
• Scabies: eliminates Sarcoptes scabiei mites, relieving itching and skin lesions.
• Pediculosis: kills head lice (Pediculus humanus capitis) and nits.

• Ivermectin binds selectively to glutamate‑gated chloride channels that are present in many invertebrates. The binding increases the permeability of the channel to chloride ions, causing an influx that hyperpolarizes neuronal and muscular cells. This results in paralysis of the parasite, loss of attachment to the host, and ultimately parasite death, while mammalian cells are largely unaffected because they lack these channels.

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

Common Side Effects

• Nausea: mild stomach upset or queasiness.
• Diarrhea: loose stools occurring shortly after dosing.
• Dizziness: transient light‑headedness or vertigo.
• Pruritus: itching sensation, often related to parasite die‑off.
• Abdominal pain: cramp‑like discomfort in the abdomen.
• Headache: mild to moderate head pain.
• Fatigue: feeling of tiredness or lack of energy.

Serious or Rare Side Effects

• Hypersensitivity reactions: rash, urticaria, or anaphylaxis in rare cases.
• Neurological events: seizures, ataxia, or altered consciousness, especially in patients with high systemic exposure.
• Hepatotoxicity: elevated liver enzymes or jaundice, reported infrequently.

When prescribing ivermectin, several safety considerations should be reviewed.

• Indication verification: confirm the specific parasitic infection and appropriate dosing regimen.
• Concomitant CNS drugs: avoid use with other agents that lower seizure threshold.
• Liver function: assess hepatic status, as metabolism occurs primarily in the liver.
• Pregnancy status: evaluate risk‑benefit, as safety data are limited.
• Age restrictions: use caution in children weighing less than 15 kg.
• Store at ambient temperature: keep in original packaging, protect from moisture and direct sunlight.

Ivermectin may interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Strong CYP3A4 inducers: drugs such as rifampicin can markedly reduce ivermectin plasma levels.
• P‑glycoprotein inhibitors: co‑administration with verapamil may increase systemic exposure.

Moderate Interactions (Monitor Closely)

• Anticoagulants: monitor INR when used with warfarin due to potential increased bleeding risk.
• CNS depressants: combined use with benzodiazepines may enhance sedation.
• Antiretrovirals: protease inhibitors can affect ivermectin metabolism; dose adjustment may be required.