Ivermectin β€” NZ Medication Guide

What is Ivermectin?

Ivermectin is an antiparasitic agent used to treat a range of parasitic infections affecting the skin, gut, and eyes. This medication is funded by Pharmac for scabies and strongyloidiasis under certain criteria.

What is Ivermectin Used For?

Ivermectin is used for scabies (topical and oral), head lice (topical β€” off-label), strongyloidiasis, onchocerciasis (river blindness), lymphatic filariasis, and cutaneous larva migrans.

How Does Ivermectin Work?

Ivermectin binds selectively and with high affinity to glutamate-gated chloride channels found in invertebrate nerve and muscle cells. This increases cell membrane permeability to chloride ions, causing hyperpolarisation of nerve and muscle cells β€” paralysis and death of the parasite. These channels are absent in mammals, giving ivermectin selective toxicity.

How to Take Ivermectin

For scabies: single oral dose of 200 mcg/kg, repeated after 1–2 weeks. Apply topical permethrin cream concurrently for skin treatment. For strongyloidiasis: 200 mcg/kg/day for 1–2 days. Take on an empty stomach with water for best absorption. Wash all bedding, clothing, and close contacts should be treated simultaneously for scabies.

Common Side Effects of Ivermectin

  • Dizziness
  • Nausea
  • Headache
  • Diarrhoea
  • Rash
  • Mazzotti reaction in onchocerciasis (fever, lymph node swelling, skin reaction β€” from dying parasites)

Serious Side Effects β€” Seek Medical Attention

Contact your doctor or call 111 immediately if you experience any of the following:

  • Encephalopathy (rare β€” particularly in patients with high Loa loa microfilariae burden β€” not applicable in NZ context)
  • Severe skin reactions (rare)
  • Neurological effects at very high doses

Drug Interactions

Ivermectin may interact with other medicines. Always inform your doctor and pharmacist of all medications you are taking. Key interactions include:

  • Warfarin (possible increased anticoagulant effect)
  • CYP3A4 inhibitors (may increase ivermectin levels)

New Zealand Prescribing Information

Ivermectin (3 mg tablets) is funded by Pharmac under Special Authority for scabies in specific circumstances and for strongyloidiasis. Community-wide treatment programmes for scabies outbreaks in NZ, particularly in Pacific Island and Māori communities, may involve public health-coordinated ivermectin distribution. Note: ivermectin has NOT been proven safe or effective for COVID-19 β€” Medsafe and the TGA advise against its use for this purpose.

Frequently Asked Questions

Is ivermectin effective for COVID-19?

No β€” multiple large, well-conducted clinical trials have found ivermectin to be no more effective than placebo for COVID-19. Medsafe, the WHO, and international health authorities do not recommend ivermectin for COVID-19 prevention or treatment. Using ivermectin for this purpose outside of clinical trials is not appropriate.

How many doses of ivermectin do I need for scabies?

For uncomplicated scabies, two oral doses are typically given β€” at day 1 and day 8 (one week apart). This is to kill any mites that hatched from eggs after the first dose. Topical permethrin cream applied on the same schedule provides the most effective treatment when used in combination.

Reviewed by a Registered Pharmacist NZ

References & Further Information

The following New Zealand and international resources were used to inform this page:

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *