Ivermectin Side Effects
For the Consumer
Applies to ivermectin: oral tablet
Along with its needed effects, ivermectin may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur while taking ivermectin:Less common—for the treatment of river blindness (onchocerciasis) only
- Eye or eyelid irritation, pain, redness, or swelling
Some side effects of ivermectin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:More common—for the treatment of river blindness (onchocerciasis) only
- Fever, itching or skin rash
- joint or muscle pain
- painful and tender glands in neck, armpits, or groin
- rapid heartbeat
- swelling of the face, hands, arms, feet, or legs
- skin rash or itching
- Lightheadedness when getting up from a lying or sitting position
- Loss of appetite
- shaking or trembling
For Healthcare Professionals
Applies to ivermectin: compounding powder, oral tablet
Ivermectin is well tolerated compared to other microfilaricidal agents (i.e., thiabendazole, diethylcarbamazine). Adverse reactions (i.e., pruritus, fever, rash, myalgia, headache) occur commonly during the first 3 days after treatment and appear to be related to the extent of parasitic infection and systemic mobilization and killing of microfilariae. The majority of reactions can usually be treated with aspirin, acetaminophen and/or antihistamines. Adverse effects tend to occur with lesser frequency during periods of retreatment.[Ref]
Ocular side effects have included eyelid edema, anterior uveitis, blurred vision, conjunctivitis, limbitis, punctate opacity, keratitis, abnormal sensation in the eyes, and chorioretinitis/choroiditis; however, these effects are also associated with the disease onchocerciasis. Loss of vision has occurred rarely but usually resolved without corticosteroid treatment. Conjunctival hemorrhage has been reported during postmarketing experience in patients treated for onchocerciasis.[Ref]
Worsening of Mazzotti reactions, including arthralgia, synovitis, lymph node enlargement and tenderness, pruritus, skin involvement (including edema, papular and pustular or frank urticarial rash), and fever, has been reported during the first 4 days following treatment for onchocerciasis.
Nervous system side effects have included dizziness, headache, somnolence, vertigo, and tremor. Serious or fatal encephalopathy has been reported rarely in patients with onchocerciases, and heavily infected with Loa loa, either spontaneously or after treatment with ivermectin. Seizures have been reported during postmarketing experience.[Ref]
Gastrointestinal side effects have included anorexia, constipation, diarrhea, nausea, vomiting, and abdominal distention.[Ref]
Other side effects have included asthenia, fatigue, abdominal pain, chest discomfort, facial edema, and peripheral edema.
Hematologic side effects have included decreased leukocyte count (3%), eosinophilia (3%), and increased hemoglobin (1%). Hematomatous swellings associated with prolonged prothrombin times have been reported, but the clinical significance is unknown. Leukopenia and anemia have been reported in at least one patient.[Ref]
Hepatic side effects have included elevated ALT and/or AST. Elevated liver enzymes, elevated bilirubin, and hepatitis have been reported during postmarketing experience.[Ref]
Cardiovascular side effects have included tachycardia and orthostatic hypotension. EKG changes, including prolonged PR interval, flattened T waves and peaked T waves, have been reported in single cases. Hypotension (primarily orthostatic hypotension) has been reported during postmarketing experience.[Ref]
Dermatologic side effects have included pruritus, rash, and urticaria. Toxic epidermal necrolysis and Stevens-Johnson syndrome have been reported during postmarketing experience.
Respiratory side effects have included worsening bronchial asthma, laryngeal edema, and dyspnea.[Ref]
Musculoskeletal side effects have included myalgia.
Renal side effects have included rare transient proteinuria.[Ref]
1. Goa KL, McTavish D, Clissold SP "Ivermectin. A review of its antifilarial activity, pharmacokinetic properties and clinical efficacy in onchocerciasis." Drugs 42 (1991): 640-58
2. Pacque M, Munoz B, Greene BM, Taylor HR "Community-based treatment of onchocerciasis with ivermectin: safety, efficacy, and acceptability of yearly treatment." J Infect Dis 163 (1991): 381-5
3. Campbell WC "Ivermectin as an antiparasitic agent for use in humans." Annu Rev Microbiol 45 (1991): 445-74
4. De Sole G, Remme J, Awadzi K, Accorsi S, Alley ES, Ba O, Dadzie KY, Giese J, Karam M, Keita FM "Adverse reactions after large-scale treatment of onchocerciasis with ivermectin: combined results from eight community trials." Bull World Health Organ 67 (1989): 707-19
5. Rothova A, van der Lelij A, Stilma JS, Wilson WR, Barbe RF "Side-effects of ivermectin in treatment of onchocerciasis." Lancet 1 (1989): 1439-41
6. Kumaraswami V, Ottesen EA, Vijayasekaran V, Devi U, Swaminathan M, Aziz MA, Sarma GR, Prabhakar R, Tripathy SP "Ivermectin for the treatment of Wuchereria bancrofti filariasis. Efficacy and adverse reactions [published erratum appears in JAMA 1988 Aug 5;260(5):640]." JAMA 259 (1988): 3150-3
7. "Product Information. Stromectol (ivermectin)." Merck & Co, Inc, West Point, PA.
8. Ette EI, Thomas WO, Achumba JI "Ivermectin: a long-acting microfilaricidal agent." DICP 24 (1990): 426-33
9. Chijioke CP, Okonkwo PO "Adverse events following mass ivermectin therapy for onchocerciasis." Trans R Soc Trop Med Hyg 86 (1992): 284-6
10. Elmogy M, Fayed H, Marzok H, Rashad A "Oral ivermectin in the treatment of scabies." Int J Dermatol 38 (1999): 926-8
11. Pacque MC, Munoz B, White AT, Williams PN, Greene BM, Taylor HR "Ivermectin and prothrombin time." Lancet 1 (1989): 1139-40
12. Homeida MM, Bagi IA, Ghalib HW, el Sheikh H, Ismail A, Yousif MA, Sulieman S, Ali HM, Bennett JL, Williams J "Prolongation of prothrombin time with ivermectin." Lancet 1 (1988): 1346-7
13. Richards FO Jr, McNeeley MB, Bryan RT, et al. "Ivermectin and prothrombin time." Lancet 1 (1989): 1139-40
14. Wijesundera MD, Sanmuganathan PS "Ivermectin therapy in chronic strongyloidiasis." Trans R Soc Trop Med Hyg 86 (1992): 291
15. delGiudice P, Bonnet H, Leotard AA, Marty P, GariToussaint M, LeFichoux Y "Ivermectin in elderly patients." Arch Dermatol 135 (1999): 351-2
Some side effects of ivermectin may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
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- Drug class: anthelmintics
Other brands: Stromectol
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