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ivermectin

Sold as Soolantra, Stromectol, Sklice. Class: Avermectines. First FDA approval 11/22/1996: 30 years on the US market.

This grade answers one narrow question: how strong is the public evidence and safety record behind this drug, and how clean is its money trail and court record? It is not a verdict on whether the drug is right for you.

B

Score breakdown (85/100)

Safety ×35%
A
Evidence ×25%
D
Regulatory ×15%
A
Money & lawsuits ×15%
A
Options ×10%
C

Safety: 95

Evidence: 61

Regulatory history: 96

Money & lawsuits: 100

Options: 70

Independent reviews and post-approval warnings

WHO Essential Medicine

Listed on the WHO Model List of Essential Medicines: a global expert panel judged it among the medicines a health system should always have, on evidence of value, not marketing.

What the FDA label says

Approved uses

INDICATIONS AND USAGE STROMECTOL is indicated for the treatment of the following infections: Strongyloidiasis of the intestinal tract . STROMECTOL is indicated for the treatment of intestinal (i.e., nondisseminated) strongyloidiasis due to the nematode parasite Strongyloides stercoralis . This indication is based on clinical studies of both comparative and open-label designs, in which 64-100% of infected patients were cured following a single 200-mcg/kg dose of ivermectin. (See CLINICAL PHARMACOLOGY, Clinical Studies .) Onchocerciasis . STROMECTOL is indicated for the treatment of onchocerciasis due to the nematode parasite Onchocerca volvulus . This indication is based on randomized, double-blind, placebo-controlled and comparative studies conducted in 1427 patients in onchocerciasis-endemic areas of West Africa. The comparative studies used diethylcarbamazine citrate (DEC-C). NOTE: STROMECTOL has no activity against adult Onchocerca volvulus parasites. The adult parasites reside in subcutaneous nodules which are infrequently palpable. Surgical excision of these nodules (nodulectomy) may be considered in the management of patients with onchocerciasis, since this procedure will eli...

Contraindications

CONTRAINDICATIONS STROMECTOL is contraindicated in patients who are hypersensitive to any component of this product.

Warnings and precautions

WARNINGS Historical data have shown that microfilaricidal drugs, such as diethylcarbamazine citrate (DEC-C), might cause cutaneous and/or systemic reactions of varying severity (the Mazzotti reaction) and ophthalmological reactions in patients with onchocerciasis. These reactions are probably due to allergic and inflammatory responses to the death of microfilariae. Patients treated with STROMECTOL for onchocerciasis may experience these reactions in addition to clinical adverse reactions possibly, probably, or definitely related to the drug itself. (See ADVERSE REACTIONS, Onchocerciasis .) The treatment of severe Mazzotti reactions has not been subjected to controlled clinical trials. Oral hydration, recumbency, intravenous normal saline, and/or parenteral corticosteroids have been used to treat postural hypotension. Antihistamines and/or aspirin have been used for most mild to moderate cases. Neurotoxicity with the use of ivermectin, including alteration of consciousness of variable severity (e.g., somnolence/drowsiness, stupor, and coma), confusion, disorientation and death, has been reported in patients without onchocerciasis or in patients with onchocerciasis in the absence of ...

Adverse reactions (label)

ADVERSE REACTIONS Strongyloidiasis In four clinical studies involving a total of 109 patients given either one or two doses of 170 to 200 mcg/kg of STROMECTOL, the following adverse reactions were reported as possibly, probably, or definitely related to STROMECTOL: Body as a Whole: asthenia/fatigue (0.9%), abdominal pain (0.9%) Gastrointestinal: anorexia (0.9%), constipation (0.9%), diarrhea (1.8%), nausea (1.8%), vomiting (0.9%) Nervous System/Psychiatric: dizziness (2.8%), somnolence (0.9%), vertigo (0.9%), tremor (0.9%) Skin: pruritus (2.8%), rash (0.9%), and urticaria (0.9%). In comparative trials, patients treated with STROMECTOL experienced more abdominal distention and chest discomfort than patients treated with albendazole. However, STROMECTOL was better tolerated than thiabendazole in comparative studies involving 37 patients treated with thiabendazole. The Mazzotti-type and ophthalmologic reactions associated with the treatment of onchocerciasis or the disease itself would not be expected to occur in strongyloidiasis patients treated with STROMECTOL. (See ADVERSE REACTIONS, Onchocerciasis .) Laboratory Test Findings In clinical trials involving 109 patients given either o...

Source: FDA SPL label for STROMECTOL (Merck Sharp & Dohme LLC), effective 20240920. Full label on DailyMed.

Side-effect reports sent to the FDA

These are counts of reports people filed, not rates of harm. Anyone can file one, and nobody checks whether the drug was the cause. Millions of doses are taken for every report sent, so the useful part is how this drug compares with the average across all drugs.

5,054reports that mention this drug
5,030of those blame this drug, not another one the person was taking
50%of reports describe a serious outcome, such as a hospital stay (average for all drugs: 57%)
8.1%of reports include a death, from any cause (average for all drugs: 9.1%)

Problems reported most often

Drug Ineffective · 744Off Label Use · 486Product Use In Unapproved Indication · 475Pruritus · 295Erythema · 236Headache · 199Rash · 190Fatigue · 171Rosacea · 161Nausea · 150Condition Aggravated · 146Diarrhoea · 144Skin Burning Sensation · 123Pain · 122Vomiting · 119

Reports per year

20192020202120222023202420252026
439366621483401409626351

Source: the FDA's Adverse Event Reporting System (FAERS). Reports are voluntary and unverified. Drugs that are prescribed a lot, in the news, or in lawsuits attract more reports, so the percentages are compared with the whole database to correct for that partly, not fully.

Recalls and regulatory record

0recall actions on file
3 / 12brand / generic applications
3label changes since 2021
NoREMS program

Evidence base

388randomized trials (PubMed)
52systematic reviews
242registered trials
34%of completed trials posted results
7%terminated or withdrawn
19%industry-funded

Independent Cochrane reviews

Counts measure how much evidence exists and how transparent it is, not how big the benefit is. For that, ask your prescriber: if 100 people like me took this, how many would get better because of it, and how many would be harmed? (Doctors call these the "number needed to treat" and "number needed to harm.") It differs by condition and is the number drug ads leave out. Sources: PubMed, ClinicalTrials.gov.

Money and lawsuits

In 2024, drug companies reported $0 in payments to US physicians and hospitals tied to this drug across 0 transactions.

No pending federal MDL names this drug or its brands.

Not named in any federal pharmaceutical settlement of $100M or more on record.

Sources: CMS Open Payments (Sunshine Act); Judicial Panel on Multidistrict Litigation pending docket list; DOJ settlements as tabulated on Wikipedia with links to the primary record. State-court and individual suits are not included.

Who takes it and what it costs

50,916Medicare Part D patients (2024)
80,931prescriptions filled
$163average cost per fill
$13Mtotal Medicare spend
ProductFills$/fill
IVermectin79,001$150
Soolantra1,911$727
Stromectol19$52

Same-class alternatives

No same-class alternatives found in RxClass.

Questions to ask your prescriber

  1. The most-reported problems in FDA's adverse event data are product use in unapproved indication, pruritus. How would we recognize and handle those?
  2. Off-label use is among the most-reported items for this drug. Is my use on-label, and if not, what evidence supports it?
  3. What result are we expecting, by when, and what is the plan if it does not happen?
  4. If 100 people like me took this drug, how many would actually get better because of it, and how many would be harmed by it? (Doctors call these the number needed to treat and the number needed to harm.)