Table 1.
Recreational drug (e.g., cannabis; opiates/opioids; amphetamine-type stimulants; and khat) misuse and its impact on male fertility levels: summary of most representative findings.
| Drug | Author | Year | Country | Study Design | Sample Size | Population Description | Outcomes Being Analyzed | Main Findings |
|---|---|---|---|---|---|---|---|---|
| Cannabis | Hehemann et al. | 2021 | U.S. | Prospective | 409 | 71 current users 103 past users |
Semen quality | Current use was associated with increased odds of abnormal morphology [OR 2.15, 95%CI: 1.21–3.79] and abnormal semen volume (OR 2.76, 95%CI: 1.19–6.42), while odds of less than WHO reference value sperm motility were reduced (OR 0.47, 95%CI: 0.25–0.91) |
| Cannabis | Carroll et al. | 2020 | Jamaica | Cross-sectional | 229 | 47% current users | Semen quality | Recent- and large-quantity use were 2.6 times (OR 2.6; 95%CI, 1.0–6.8) and 4.3 times (OR 4.3; 95%CI, 1.1–15.9) at greater risk of asthenozoospermia. Moderate quantity users were 3.4 times (OR 3.4; 95%CI, 1.5–7.9) more likely to be diagnosed with teratozoospermia |
| Cannabis | Gundersen et al. | 2015 | Denmark | Prospective | 1215 | 45% recent users | Semen quality, reproductive hormone levels | Regular marijuana smoking associated with a 28% (95%CI: −48, −1) lower sperm concentration and a 29% (95%CI: −46, −1) lower total sperm count. The combined use of marijuana and other recreational drugs reduced the sperm concentration by 52% (95%CI: −68, −27) and total sperm count by 55% (95%CI: −71, −31). Marijuana smokers had higher levels of testosterone |
| Cannabis | Nassan et al. | 2019 | U.S. | Cross-sectional | 662 | 365 patients never used cannabis | Semen quality, reproductive hormone levels | Men who had ever smoked marijuana had significantly higher sperm concentration (62.7 million/mL (95%CI: 56.0, 70.3)) than men who had never smoked marijuana ((45.4 million/mL (38.6, 53.3)). No significant differences in sperm concentration between current and past marijuana smokers. A similar pattern was observed for total sperm count. Marijuana smokers had significantly lower FSH concentrations than never marijuana smokers |
| Opiates/opioids | Nazmara et al. | 2020 | Iran | Case-control | 48 | 24 addicted 24 healthy controls |
Semen quality, levels of protamine-2gene and miRNA-122 in seminal plasma | White blood cell count in semen (1.69 ± 0.41 vs. 8.61 ± 1.73, p = 0.001), motility (65.51 ± 2.57 vs. 41.96 ± 3.58, p = 0.001) and survival rate (87.41 ± 1.00 vs. 71.50 ± 4.59, p = 0.002) of sperm cells was significantly different between the healthy and addicted groups. Protamine-2 gene and protein expression in the addicted group were significantly lower than the healthy group, whilst seminal miRNA-122 levels in addicted men were higher than in healthy men |
| Opiates/opioids | Nazmara et al. | 2019 | Iran | Case-control | 50 | 25 heroin abusers 25 healthy controls |
Semen quality, sexual hormones levels, sperm histone replacement abnormalities | Sperm motility, viability, and sperm histone replacement abnormalities were significantly different in addicted group vs. non-exposed ones (p < 0.05). Serum sex hormone levels were not significantly different between groups |
| Opiates/opioids | Safarinejad et al. | 2012 | Iran | Case-control | 288 | 142 heroin abusers 146 healthy controls |
Semen quality, sperm function, seminal plasma antioxidant capacity, sperm DNA integrity | The mean ± SD sperm concentration in opiate users and in control subjects was 22.2 ± 4.4 and 66.3 ± 8.3 million per ml, respectively (p = 0.002). A significant increase in the amount of fragmented DNA was found in opiate consumers compared with that in controls (36.4 ± 3.8% vs. 27.1 ± 2.4%, p = 0.004). Significantly decreased levels of catalase-like and superoxide dismutase-like activity were observed in heroin abusers |
| Opiates | Bassiony et al. | 2020 | Egypt | Case-control | 90 | 60 tramadol abusers 30 healthy controls |
Semen quality, sexual hormones levels | Tramadol abusers had higher prolactin and lower free testosterone levels and they were more likely to have lower sperm counts and higher levels of abnormal motility and abnormal sperm morphology |
| Amphetamine-type stimulants (ATS) | Pham et al. | 2022 | U.S. | Retrospective cohort study | 8861 | 106 men out of the total were prescribed with stimulants for ADHD | Semen quality | Stimulant use was associated with reduced total motile sperm count in the setting of decreased semen volume, but not sperm concentration, motility and morphology |
| Amphetamine-type stimulants (ATS) | Shalev et al. | 2021 | Israel | Retrospective cohort study | 9769 | 293 men out of the total were prescribed with methylphenidate | Semen quality | Methylphenidate exposure did not affect sperm morphology but was associated with increased sperm concentration as well as increased total sperm count and total sperm motility among current and past users |
| Herbal highs/Khat | Hakim et al. | 2002 | Ethiopia | Prospective cross-sectional | 214 | 184 khat users 30 healthy controls |
Semen quality | No statistically significant difference in seminal quality parameters between groups |
Abbreviations: CI: confidence interval; DNA: deoxyribonucleic acid; FSH: follicle-stimulating hormone; miRNA-122: microribonucleic acid-122; OR: odds ratio; SD: standard deviation; U.S.: United States; WHO: World Health Organization.