**5.2 Ivermectin's potential as an anti-viral**

Ivermectin exhibits anti-viral activity against viruses both *in vitro* and *in vivo*. The antiviral activity is thought to be related to tthe inhibition of nuclear translocation of viral proteins, facilitated by mammalian host importin also known as karyopherin α/β‐1 heterodimerization [42]. It is partially upon this basis that ivermectin has been tested as a treatment in the current COVID-19 pandemic. A recent meta-analysis and systematic review involving 629 COVID-19 patients from 4 observational studies (3 with control arms and 1 without) found that adding ivermectin led to significant clinical improvement compared to control (OR=1.98, 95% CI: 1.11 - 3.53, p=0.02) [43]. however, the authors did caution on the interpretation of their analysis because the low quality of evidence, and it should be noted that one of the trials included in the analysis was subsequently retracted. Meanwhile, several randomized studies evaluating ivermectin against COVID-19 have recently been published. An Iranian trial demonstrated that a single 0.2 mg/Kg dose of ivermectin was well-tolerated in symptomatic COVID-19 patients, and dyspnea, cough and lymphopenia associated with COVID-19 were significantly improved [44]. In two other randomized trials, the time to viral clearance was statistically reduced. The doses and schedules in these two trials were ivermectin at a fixed 12 mg daily for 5 days [45] and ivermectin at 0.1, 0.2, and 0.4 mg/Kg once at admission [46]. These were underpowered trials so that further evidence is still required to confirm the clinical usefulness of ivermectin under various COVID-19 clinical scenarios.

#### **5.3 Other uses of ivermectin**

Ivermectin possesses possible agonistic bioactivity against the γ-aminobutyric acid (GABA) receptor [47] and it was upon this premise that it was used in a patient with severe spasticity caused by spinal cord damage at a dose of 1.6 mg/

*Ivermectin: Potential Repurposing of a Versatile Antiparasitic as a Novel Anticancer DOI: http://dx.doi.org/10.5772/intechopen.99813*

Kg subcutaneously twice a week for 12 weeks. The patients had decreased spasm scores, suggesting that ivermectin may reduce spasticity in the spine without adverse effects at this high dose [48].
