TABLE 4.
Interaction between antibiotics, antifungals, antiretrovirals, and cannabis.
| Drugs | Probability | Severity | Observed effects | Patient outcomes | Recommendation | References |
|---|---|---|---|---|---|---|
| Antibiotics | ||||||
| Rifampicin (Perpetrator—CYP3A4 induction) | Defined | Minor (36%–87%) |
C max of THC, CBD, and THC metabolite in the form of 11‐hydroxy‐THC (11‐OH‐THC) with the use of THC/CBD oromucosal spray alone appeared to be 2.94 ng/mL, 1.03 ng/mL, and 3.38 ng/mL, respectively With the co‐administration of THC/CBD spray and rifampicin, C max of THC, CBD, and 11‐OH‐THC were reduced to 1.88 ng/mL, 0.50 ng/mL, and 0.45 ng/mL, respectively. Overall, C max reduced by 26–87% |
Adverse effects were insignificant. Headache was reported in a limited number of participants (n = 1) | Dose increments of THC/CBD spray may be needed when rifampicin is co‐administered to achieve a similar efficacy as using THC/CBD spray alone | 11 |
| Antifungals | ||||||
| Ketoconazole (Perpetrator—CYP3A4 inhibition) | Defined | Minor to moderate (27%–204%) |
Elevations in the C max of THC, CBD, and 11‐OH‐THC were seen in subjects receiving both THC/CBD oromucosal spray and ketoconazole C max of THC increased from 2.65 to 3.36 ng/mL, whereas the C max of CBD increased from 0.66 to 1.25 ng/mL. C max increased from 3.59 to 10.92 ng/mL for 11‐OH‐THC. Overall, 36%–87% of C max was increased |
The adverse effects reported mainly involved nervous system disorders (e.g., somnolence, dizziness, and malaise) and psychiatric disorders (e.g., euphoria, anxiety, and disorientation) | Reduction in the daily dose of THC/CBD spray may be required when it is co‐administered with ketoconazole. This will maintain the efficacy of THC/CBD spray and prevent the occurrence of adverse effects | 11 |
| Antiretrovirals | ||||||
| Indinavir (Victim—Possible CYP3A and CYP2C induction) | Possible | Not applicable | Decrease in C max of indinavir by 17.4% (n = 11) | PK changes were unlikely to impact antiretroviral efficacy. Long‐term consequences were likely to be negligible, especially with the increasing use of protease inhibitor (PI) boosters | Constant monitoring of serum indinavir levels is needed. Increase the frequency of follow‐ups to review treatment efficacy | 12 |
| Nelfinavir (Victim—Possible CYP3A and CYP2C induction) | Possible | Not applicable | Decrease in C max of nelfinavir by 14.1% (n = 14) | PK changes were unlikely to impact antiretroviral efficacy. Long‐term consequences were likely to be negligible, especially with the increasing use of PI boosters | Constant monitoring of serum nelfinavir levels is needed. Increase the frequency of follow‐ups to review treatment efficacy | 12 |