Ivermectin Dosage/Ivermectin is 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.
Mechanism of Action of Ivermectin
Ivermectin binds selectively and with high affinity to glutamate-gated chloride ion channels in invertebrate muscle and nerve cells of the microfilaria. This binding causes an increase in the permeability of the cell membrane to chloride ions and results in hyperpolarization of the cell, leading to paralysis and death of the parasite. Ivermectin also is believed to act as an agonist of the neurotransmitter gamma-aminobutyric acid (GABA), thereby disrupting GABA-mediated central nervous system (CNS) neurosynaptic transmission. Ivermectin may also impair normal intrauterine development of O. volvulus microfilariae and may inhibit their release from the uteri of gravid female worms.
Indications of Ivermectin
- For the treatment of intestinal (i.e., nondisseminated) strongyloidiasis due to the nematode parasite Strongyloides stercoralis. Also for the treatment of onchocerciasis (river blindness) due to the nematode parasite Onchocerca volvulus. Can be used to treat scabies caused by Sarcoptes scabiei.
- Filariasis
- Onchocerciasis
- Strongyloidiasis
- Ascariasis
- Cutaneous Larva Migrans
- Acne Rosacea
- Ascaris lumbricoides infection
- Cutaneous larva migrans
- Demodicosis
- Gnathostomiasis
- Mansonella ozzardi infection
- Mansonella streptococcal infection
- Oesophagostomiasis
- Onchocerciasis
- Pediculosis Capitis
- Scabies
- Trichuriasis
- Wuchereria bancroftian infection
Contraindications of Ivermectin
- Infection by the worm Loa Loa
- Abnormal liver function tests
- Kidney disease with a reduction in kidney function
- Diarrhea
- The high amount of magnesium in the blood
- Low amount of sodium in the blood
- Extreme loss of body water
- Appendicitis
- Stomach or intestine blockage
- Seizures
Allergies
- Avermectins
- Ivermectin
Dosage of Ivermectin
Strengths: 3 mg; 6 mg
Filariasis
- 0.2 mg/kg orally once
- Bancroftian filariasis: 0.4 mg/kg orally once yearly (with a single annual dose of diethylcarbamazine 6 mg/kg), for 4 to 6 years.
Onchocerciasis
- 0.15 mg/kg orally once every 12 months
- Patients with heavy ocular infection may require retreatment every 6 months. Retreatment may be considered at intervals as short as 3 months.
Dosage guidelines based on body weight
- 15 to 25 kg: 3 mg orally one time
- 26 to 44 kg: 6 mg orally one time
- 45 to 64 kg: 9 mg orally one time
- 65 to 84 kg: 12 mg orally one time
- 85 kg or more: 0.15 mg/kg orally one time
Strongyloidiasis
- 0.2 mg/kg orally once
- In immunocompromised (including HIV) patients, the treatment of strongyloidiasis may be refractory requiring repeated treatment (i.e., every 2 weeks) and suppressive therapy (i.e., once a month), although well-controlled studies are not available. A cure may not be achievable in these patients.
Dosage guidelines based on body weight
- 15 to 24 kg: 3 mg orally one time
- 25 to 35 kg: 6 mg orally one time
- 36 to 50 kg: 9 mg orally one time
- 51 to 65 kg: 12 mg orally one time
- 66 to 79 kg: 15 mg orally one time
- 80 kg or more: 0.2 mg/kg orally one time
Ascariasis
- 0.2 mg/kg orally once
Pediatric Dose for Filariasis
- Bancroftian filariasis – 5 years or older: 0.4 mg/kg orally once yearly (with a single annual dose of diethylcarbamazine 6 mg/kg), for 4 to 6 years.
Side Effects of Ivermectin
More common
- signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
- Fever, itching or skin rash
- joint or muscle pain
- burning feeling of the skin
- dry skin
- itchiness
- skin irritation
- severe skin irritation
- painful and tender glands in neck, armpits, or groin
- rapid heartbeat
Less common
- Headache
- swelling of the face, hands, arms, feet, or legs
- Diarrhea
- dizziness
- skin rash or itching
- Lightheadedness when getting up from a lying or sitting position
Rare
- Loss of appetite
- shaking or trembling
- sleepiness
- change in vision
- chest pain or tightness
- confusion
- a cough
- Agitation
- arm, back, or jaw pain
- blurred vision
- chest pain or discomfort
- convulsions
- extra heartbeats
- hallucinations
- a headache
- irritability
- lightheadedness
Drug Interactions of Ivermectin
Ivermectin may interact with following drugs, supplements, & may change the efficacy of the drug
- aluminum hydroxide
- aspirin
- dextroamphetamine
- albendazole
- diphenhydramine
- praziquantel
- prednisone
- pyrantel
- acetaminophen)
- Vitamin B Complex 100 (multivitamin)
- Vitamin B12 (cyanocobalamin)
- Vitamin C (ascorbic acid)
- Vitamin D3 (cholecalciferol)
- alprazolam
- cetirizine
- voriconazole
- tacrolimus
- telaprevir
- telithromycin
- telotristat
- temsirolimus
- ribociclib
- ritonavir
- rucapari
- nelfinavir
- nevirapine
- nilotinib
- oxcarbazepine
- posaconazole
- rufinamide
- stiripentol
- modafinil
-
saquinavir
-
nefazodone
-
warfarin
Pregnancy Category of Ivermectin
Pregnancy
This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding
It is not known if ivermectin applied to the skin passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding. The safety and effectiveness of using this medication have not been established for children.
References
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