Ivermectin

 

 

Ivermectin is a medication used to treat many types of parasite infestations.

 

It kills pathogens by interfering with nervous system and muscle function, in particular by enhancing inhibitory neurotransmission.

 

It binds to glutamate-gated chloride channels in the membranes of invertebrate nerve and muscle cells, causing increased permeability to chloride ions, resulting in cellular hyper-polarization, followed by paralysis and death.

 

Parasite infestations includes: head lice, scabies, onchocerciasis, strongyloidiasis, trichuriasis, ascariasis, and lymphatic filariasis.

Oral ivermectin is effective in eradicating scabies, often in a single dose, and it is the treatment of choice for crusted scabies, and is sometimes prescribed in combination with a topical agent.

It is not recommended for children under six years of age.

Oral ivermectin is usually effective for treatment of scabies, it does have a higher treatment failure rate than topical permethrin.

Scabies is markedly reduced in populations taking ivermectin regularly.

Ivermectin drug is widely used for treating scabies and other parasitic diseases particularly among the poor and disadvantaged in the tropics.

It can be taken by mouth, but may be applied to the skin for external infestations.

 

Exposure to the eyes should be avoided.

 

Pregnancy category US: C (Risk not ruled out)

 

Protein binding 93%.

 

Metabolism by Liver (CYP450).

 

Elimination half-life 18 hours.

 

Excretion Feces, with  less than 1% urine

 

Side effects include: red eyes, dry skin, and burning skin.

 

Probably safe during breastfeeding.

 

Causes parasite’s cell membrane to increase in permeability, resulting in paralysis and death.

 

In other animals, it is used to prevent and treat heartworm and acariasis.

 

Ivermectin is as effective as albendazole or alternative antinematode drugs for treatment of pinworm infection.

 

It is used for prevention, treatment, and control of river blindness (onchocerciasis) where the disease is common. 

 

Its use is contraindicated in patients  with a high burden of loa microfilariae, due to risk of ivermectin-associated severe inflammatory events.

 

A single dose of ivermectin reduces microfilaridermia by 98-99% after 1-2 months.

 

Ivermectin does not kill adult worms. 

 

A single oral dose of ivermectin, taken once or twice a year for the 10-15-year lifespan of the adult worms, is required to protect the individual from river blindness.

 

A single dose of ivermectin gives a markedly and durably decreases in body burden of eyeworm, Loa loa.

 

Ivermectin is effective for treatment of threadworm (strongyloidiasis). 

 

Combination therapy with ivermectin plus albendazole is effective for treatment of whipwor, and lymphatic filariasis due to Wuchereria bancrofti,[22] Brugia malayi, or Brugia timori.

 

Evidence supports its use against parasitic arthropods and insects:

 

Mites such as scabies.

 

Lice- Ivermectin lotion

 

Bedbugs

 

Malaria-bearing mosquitos

 

Rosacea

 

It is contraindicated in children under the age of five or those who weigh less than 33 pounds), and individuals with liver or kidney disease.

 

Ivermectin is secreted in very low concentration in breast milk, and its safety during pregnancy is unknown.

 

Neurotoxicity, may manifest as central nervous system depression, and consequent ataxia, as might be expected from potentiation of inhibitory GABA-ergic synapses.

 

The risk of increased absorption and entry past the blood-brain barrier exists when ivermectin is administered along with other CYP3A4 inhibitors: statins, HIV protease inhibitors, many calcium channel blockers, lidocaine, the benzodiazepines, and glucocorticoids such as dexamethasone.

 

A  macrocyclic lactone derived from the bacterium Streptomyces avermitilis. 

 

It can be given by mouth, topically, or via injection. 

 

It does not readily cross the blood-brain barrier of mammals 

 

Due to the presence of P-glycoprotein, it does not readily cross the blood-brain barrier.

 

At high dose brain levels peak 2-5 hours after administration.

 

It  is routinely used to control parasitic worms in the gastrointestinal tract of ruminant animals, and in dogs it is routinely used as prophylaxis against heartworm.

 

Dogs with defects in the P-glycoprotein gene (MDR1), can be poisoned by ivermectin. 

 

Kittens are susceptible to ivermectin toxicity.

 

Use in turtles is contraindicated.

 

It has antiviral effects against several distinct positive-sense single-strand RNA viruses, including SARS-CoV-2.

Its use did not result in a lower incidence of medical admission to a hospital due to progression of Covid-19 or prolonged emergency department observation among patients with an early diagnosis of Covid-19 (Reis G).

Among our patients with mild to moderate Covid – 19 treatment with ivermectin compared with placebo did not significantly improve time to recover (Naggie S)