Ivermectin Side Effects
Commonly reported side effects of ivermectin include: fever, pruritus, and skin rash. See below for a comprehensive list of adverse effects.
For the Consumer
Applies to ivermectin: oral tablet
In addition to its needed effects, some unwanted effects may be caused by ivermectin. In the event that any of these side effects do occur, they may require medical attention.
If any of the following side effects occur while taking ivermectin, check with your doctor or nurse as soon as possible:Less common—for the treatment of river blindness (onchocerciasis) only
- Eye or eyelid irritation, pain, redness, or swelling
Minor Side Effects
Some of the side effects that can occur with ivermectin may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional: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. 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
6. 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
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
Not all side effects for ivermectin may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.
More about ivermectin
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Interactions
- Support Group
- Pricing & Coupons
- En Español
- 6 Reviews – Add your own review/rating
- Drug class: anthelmintics
Other brands: Stromectol
Related treatment guides
Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.