II. Indications
- Scabies (refractory to Permethrin 5%)
- Head Lice
- Strongyloidiasis
- Onchocerciasis
III. Contraindications
- Pregnancy first trimester
- Weight <15 kg
IV. Mechanism
- Developed initially as veterinary anti-parasitic agent
- Related to macrolide Antibiotics
- Decreases Nerve Impulse transmission
V. Medications
- Ivermectin 3 mg tablet
- Dose 200 mcg/kg equivalents
- Weight 15 to 24 kg: 3 mg
- Weight 25 to 35 kg: 6 mg
- Weight 36 to 50 kg: 9 mg
- Weight 51 to 65 kg: 12 mg
- Weight 66 to 79 kg: 15 mg
VI. Dosing: FDA Approved for Adult and Child (weight >=15 kg)
-
General
- Take on an empty Stomach with water
-
Strongyloidiasis
- Ivermectin 200 mcg/kg orally for 1 dose
- Consider repeat up to monthly doses in Immunocompromised patients (e.g. HIV Infection)
- Onchocerciasis
- Ivermectin 150 mcg/kg orally for 1 dose, repeated every 3 to 12 months
VII. Dosing: Off-Label for Adult and Child (weight >=15 kg)
-
Scabies or Head Lice (not FDA approved)
- Ivermectin 200 mcg/kg orally for 1 dose, and repeat dose in 10 days
-
Crusted Scabies
- Ivermectin 200 mcg/kg orally on days 1, 2, 8, 9, 15 (and consider on days 22 and 29 in more severe cases)
- Use in combination with full body Permethrin 5% daily for 7 days, then twice daily until resolution
- Public Lice
- Ivermectin 250 mcg/kg orally, then repeated in 2 weeks
-
Cutaneous Larva Migrans
- Ivermectin 200 mcg/kg orally daily for 1 to 2 days
- Roundworm Infections
- Ivermectin 150 to 200 mcg/kg orally for 1 dose
VIII. Pharmacokinetics
- Peak Level: 3-6 hours after intake
- Half-Life: >12 hours
- Metabolized by Cyp 3A4
- Crosses blood brain barrier via P-Glycoprotein (ABCB1 Transporter)
IX. Adverse Effects: Mazzotti Reaction (Immunologic Reaction in Onchocerciasis to Parasite Death)
- Nausea
- Fever
- Headache
- Arthralgias
- Urticaria
- Ophthalmic complications
X. Adverse Effects: Toxicity or Overdose
- Background
- Lower Doses <500 mg in adults and <5mg/kg in children are typically without reaction
- High doses, however, may result in life threatening adverse effects (Seizures, coma, death)
- In 2021, patients were taking very high doses (>600 mg daily) for COVID-19 (based on little evidence of benefit)
- Patients also ingested high risk formulations (topical Ivermectin, veterinary Ivermectin)
- Findings typically resolve within 6-8 hours of ingestion
- Gastrointestinal Findings
- Neurologic Findings
- Headache
- Dizziness
- Hallucinations
- Confusion
- Cardiopulmonary Findings
- Skin Findings
- Management
- See Unknown Ingestion
- Activated Charcoal
- Indicated in early presentation of large ingestion
- Supportive Management
- ABC Management
- Benzodiazepines for Seizures
- Consider Intravenous Lipid Emulsion
XI. Safety
XII. Efficacy: Scabies
- Studies show efficacy over Lindane for Scabies
- Permethrin 5% appears to be more effective for Scabies
XIII. Drug Interactions
-
Warfarin
- Ivermectin may increase INR levels
XIV. Resources
- Ivermectin Tablet (DailyMed)
XV. References
- Hamilton (2020) Tarascon Pocket Pharmacopoeia
- Tomaszewski (2021) Crit Dec Emerg Med 35(9): 32
- Meinking (1995) N Engl J Med 333:26 [PubMed]
- Fawcett (2003) Am Fam Physician 68(6):1089-92 [PubMed]
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ivermectin (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
IVERMECTIN 1% CREAM | Generic | $5.01 per gram |
IVERMECTIN 3 MG TABLET | Generic | $3.68 each |
Ontology: Ivermectin (C0022322)
Definition (NCI) | A macrocyclic lactone derived from Streptomyces avermitilis with antiparasitic activity. Ivermectin exerts its anthelmintic effect via activating glutamate-gated chloride channels expressed on nematode neurons and pharyngeal muscle cells. Distinct from the channel opening induced by endogenous glutamate transmitter, ivermectin-activated channels open very slowly but essentially irreversibly. As a result, neurons or muscle cells remain at either hyperpolarisation or depolarization state, thereby resulting in paralysis and death of the parasites. Ivermectin does not readily pass the mammal blood-brain barrier to the central nervous system where glutamate-gated chloride channels locate, hence the hosts are relatively resistant to the effects of this agent. |
Definition (MSH) | A mixture of mostly avermectin H2B1a (RN 71827-03-7) with some avermectin H2B1b (RN 70209-81-3), which are macrolides from STREPTOMYCES avermitilis. It binds glutamate-gated chloride channel to cause increased permeability and hyperpolarization of nerve and muscle cells. It also interacts with other CHLORIDE CHANNELS. It is a broad spectrum antiparasitic that is active against microfilariae of ONCHOCERCA VOLVULUS but not the adult form. |
Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
MSH | D007559 |
SnomedCT | 387559003, 96138006 |
English | Ivermectin, ivermectin, ivermectin (medication), IVERMECTIN, Ivermectin [Chemical/Ingredient], Avermectin A1a, 5-O-demethyl-25-de(1-methylpropyl)-22,23-dihydro-25-(1-methylethyl)-, Ivermectin (product), Ivermectin (substance) |
Swedish | Ivermektin |
Czech | ivermektin |
Finnish | Ivermektiini |
Russian | IVERMEKTIN, ИВЕРМЕКТИН |
Japanese | イベルメクチン |
Polish | Iwermektyna, Ivermectin |
Spanish | ivermectina (producto), ivermectina (sustancia), ivermectina, Ivermectina |
French | Ivermectine |
German | Ivermectin |
Italian | Ivermectina |
Portuguese | Ivermectina |
Ontology: Stromectol (C0723477)
Definition (MSH) | Oral preparation of ivermectin. |
Concepts | Organic Chemical (T109) , Pharmacologic Substance (T121) |
MSH | D007559 |
English | Stromectol, Ivermectin Merck Brand, Merck Brand of Ivermectin |
Ontology: Mectizan (C0751253)
Concepts | Organic Chemical (T109) , Pharmacologic Substance (T121) |
MSH | D007559 |
English | Mectizan |