Dosing and uses of Stromectol (ivermectin)
Adult dosage forms and strengths
tablet
- 3mg
Strongyloidiasis of the Intestinal Tract
15-24 kg: 3 mg PO once
25-35 kg: 6 mg PO once
36-50 kg: 9 mg PO once
51-65 kg: 12 mg PO once
66-79 kg: 15 mg PO once
>80 kg: 200 mcg/kg PO once
Dosing considerations
- In general repeat doses not necessary; perform stool examinations to verify eradication of infection
River Blindness (Onchocerciasis)
15-25 kg: 3 mg PO; may repeat in 3-12 mo
26-44 kg: 6 mg PO; may repeat in 3-12 mo
45-64 kg: 9 mg PO; may repeat in 3-12 mo
65-84 kg: 12 mg PO; may repeat in 3-12 mo
≥85 kg: 150 mcg/kg PO; may repeat in 3-12 mo
Dosing considerations
- Note: Does not treat adult worms (must be surgically excised)
Head Lice (Pediculosis capitis; Off-label)
200 mcg/kg PO once; may require 1-2 additional doses repeated after 7 days
Blepharitis (Demodex folliculorum; Off-label)
200 mcg/kg PO once as a single dose, THEN repeat dose once in 7 days
Filariasis Due to Mansonella Ozzardi (Off-label)
6 mg PO as single dose
Filariasis Due to Mansonella Streptocera (Off-label)
150 mcg/kg as single dose
Scabies Due to Sarcoptes Scabiel
Immunocompromised patients: 200 mcg/kg as single dose; may repeat in 14 days if necessary
Gnathostoma Spinigerum
Gnathostomiasis: 200 mcg/kg as single dose
Administration
Take on empty stomach
Monitor: Stool exams (Strongyloides)
Pediatric dosage forms and strengths
tablet
- 3mg
River Blindness (Onchocerciasis)
<15 kg: Safety and efficacy not established
15-25 kg: 3 mg PO; may repeat in 3-12 mo
26-44 kg: 6 mg PO; may repeat in 3-12 mo
45-64 kg: 9 mg PO; may repeat in 3-12 mo
65-84 kg: 12 mg PO; may repeat in 3-12 mo
≥85 kg: 150 mcg/kg PO; may repeat in 3-12 mo
Dosing considerations
- Note: Does not treat adult worms (must be surgically excised)
Strongyloidiasis of the Intestinal Tract
<15 kg: Safety and efficacy not established
15-24 kg: 3 mg PO once
25-35 kg: 6 mg PO once
36-50 kg: 9 mg PO once
51-65 kg: 12 mg PO once
66-79 kg: 15 mg PO once
>80 kg: 200 mcg/kg PO once
Dosing considerations
- In general repeat doses not necessary; perform stool examinations to verify eradication of infection
Administration
Take on empty stomach
Monitor: Stool exams (Strongyloides)
Stromectol (ivermectin) adverse (side) effects
Frequency not defined
Abdominal pain
Asthenia
Hypotension
Mild EKG changes
Peripheral & facial edema
Transient tachycardia
Dizziness
Headache
Hyperthermia
Insomnia
Somnolence
Vertigo
Pruritus
Rash
Urticaria
Diarrhea
Nausea
Vomiting
Eosinophilia
Leukopenia
ALT/AST increased
Limbitis
Myalgia
Tremor
Blurred vision
Mild conjunctivitis
Punctate opacity
Mazzotti reaction (with onchocerciasis)
Edema
Fever
Lymphadenopathy
Ocular damage
Pruritus rash
Conjunctival hemorrhage (with onchocerciasis)
Hepatitis
Warnings
Contraindications
Hypersensitivity to ivermectin
Cautions
May cause cutaneous and/or systemic reactions
Does not kill adult Onchocerca volvulus, only microfilariae
Not active against disseminated Strongyloides, only intestinaL
Potential risk of Mazzotti reactions (cutaneous and systemic adverse effects)
May be required to repeat treatments in immunocompromised patients
Suppressive therapy (monthly) may be necessary to control extraintestinal strongyloidiasis
Perform pretreatment assessment for Loa loa infection in any patient with significant exposure to endemic areas; serious and/or fatal encephalopathy reported during treatment in patients with loiasis
Pregnancy and lactation
Pregnancy category: C
Lactation: Enters breast milk (AAP Committee states compatible with nursing)
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Stromectol (ivermectin)
Mechanism of action
Binds glutamate-gated Cl ion channels in invertebrate nerve and muscle cells; produces paralysis, death of parasite
Absorption
Well absorbed
Peak serum time: 4 hr
Peak effect: 3-6 months (treatment of orchocerciasis); 3 months (treatment of strongyloides)
Distribution
Protein bound: 93%
Vd: 3-3.5 L/kg
Does not cross blood-brain barrier
Metabolism
Hepatic (CYP3A4, CYP2D6, CYP2E1)
Elimination
Half-life: 18 hr
Excretion: Feces; urine (<1%)
