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Moxidectin

Medically reviewed by Drugs.com. Last updated on Aug 28, 2023.

Pronunciation

(mox i DEK tin)

Dosage Forms

Tablet, oral

Generic: 2 mg [500s] [contains lactose, sodium lauryl sulfate]

Pharmacologic Category

Pharmacology

Moxidectin, an anthelminthic agent, is active against the microfilariae of O. volvulus, but not effective in killing the adult worms. Studies with other nematodes suggest moxidectin binds to glutamate-gated chloride ions channels, gamma-aminobutyric acid (GABA) receptors, and/or APT-binding cassette transporters. This leads to increased permeability, influx of chloride ions, hyperpolarization, and muscle paralysis. There is also a reduction in motility of all stages of the parasite, excretion of immunomodulatory proteins, and the fertility of both male and female adult worms.

Distribution

Vd: 2,421 ± 1,658 L

Metabolism

Minimal

Excretion

Feces: 2% (as unchanged drug)

Time to Peak

4 hours

Half-Life Elimination

23.3 days (559 hours)

Protein Binding

Unknown

Use: Labeled Indications

Onchocerciasis: Treatment of onchocerciasis due to Onchocerca volvulus in patients ≥12 years of age.

Limitations of use: Moxidectin does not kill adult O. volvulus; follow-up evaluation is advised. Safety and efficacy of repeat administration of moxidectin in patients with O. volvulus has not been studied.

Contraindications

There are no contraindications listed in the manufacturer’s labeling.

Dosing: Adult

Onchocerciasis: Oral: 8 mg as a single dose

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Onchocerciasis: Children ≥12 years and Adolescents: Oral: 8 mg as a single dose

Administration

Oral: Administer without regard to meals.

Storage

Store below 30°C (86°F). Protect from light. Once opened, administer within 24 hours. Discard unused tablets.

Drug Interactions

There are no known significant interactions.

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.

>10%:

Cardiovascular: Tachycardia (39%), postural orthostatic tachycardia (34%), hypotension (30%), orthostatic hypotension (22%), peripheral edema (11%)

Central nervous system: Headache (58%), chills (≤27%), lymph node pain (13%), dizziness (12%)

Dermatologic: Pruritus (65%), skin rash (37%)

Endocrine & metabolic: Hyponatremia (12%)

Gastrointestinal: Abdominal pain (31%), diarrhea (≤15%), enteritis (≤15%), gastroenteritis (≤15%)

Hematologic & oncologic: Eosinophilia (18% to 74%; severe: 18%), lymphocytopenia (48%: grade 3: 23%), leukocytosis (25%), neutropenia (20%: grade 4: 7%)

Neuromuscular & skeletal: Musculoskeletal pain (64%)

Respiratory: Flu-like symptoms (23%), cough (17%)

Miscellaneous: Fever (≤27%)

1% to 10%:

Cardiovascular: Symptomatic orthostatic hypotension (5%)

Endocrine & metabolic: Increased gamma-glutamyl transferase (3%)

Hematologic & oncologic: Eosinopenia (5%)

Hepatic: Hyperbilirubinemia (3%), increased serum alanine aminotransferase (1%), increased serum aspartate aminotransferase (1%)

Ophthalmic: Eye pain (8%), eye pruritus (7%), visual impairment (3%; including blurred vision, low vision acuity), allergic conjunctivitis (2%), eyelid edema (2%), conjunctival hyperemia (≤2%), ocular hyperemia (≤2%), increased lacrimation (1%)

Frequency not defined: Dermatologic: Mazzotti reaction

Warnings/Precautions

Concerns related to adverse effects:

• Mazzoti reaction: Moxidectin treatment may cause cutaneous, ophthalmological, and/or systemic reactions (Mazzoti reaction) of varying severity, due to allergic and inflammatory host responses to the death of microfilariae. These reactions generally occur and resolve in the first week post-treatment. Risk may be increased in patients with higher microfilarial burden. Treatment of severe Mazzoti reactions is not definitive, but includes supportive care (eg, hydration and/or parenteral corticosteroids) to treat postural hypotension. Antihistamines and/or aspirin have been used for most mild to moderate reactions.

• Orthostatic hypotension: Orthostatic hypotension may occur, most commonly on the first 1 to 2 days after treatment. Decrease in blood pressure was transient and managed by resuming recumbency.

Disease-related concerns:

• Loiasis: Pretreatment assessment for loiasis is recommended in any patient with exposure to Loa loa-endemic areas; serious, sometimes fatal, encephalopathy may occur following treatment with moxidectin in onchocerciasis patients with concomitant loiasis.

Other warnings/precautions:

• Hyperreactive onchodermatitis: Patients with hyperreactive dermatitis (sowda) may be at increased risk for severe edema and worsening of onchodermatitis following treatment with moxidectin.

Monitoring Parameters

Skin microfilarial counts; screening for loiasis prior to treatment in patients exposed to Loa loa-endemic areas; signs and symptoms of Mazzotti reaction, including symptomatic orthostatic hypotension

Reproductive Considerations

Females of reproductive potential were required to use long acting contraception during clinical studies (Awadzi 2014; Korth-Bradley 2011) likely due to the long terminal half-life of moxidectin.

Pregnancy Considerations

Adverse events were observed in some animal reproduction studies.

Patient Education

What is this drug used for?

• It is used to treat eye and skin disease caused by certain worms (O. volvulus).

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Abdominal pain

• Diarrhea

• Cough

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Low sodium like headache, trouble focusing, trouble with memory, confusion, weakness, seizures, or change in balance.

• Infection

• Itching

• Headache

• Flu-like symptoms

• Dizziness

• Passing out

• Fast heartbeat

• Swollen glands

• Muscle pain

• Joint pain

• Chills

• Weakness

• Burning or numbness feeling

• Eye redness

• Eye pain

• Eye itching

• Eye swelling

• Blurred vision

• Watery eyes

• Light sensitivity

• Swelling

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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