This approach to dealing with substance use disorder is to treat it as a medical problem and focusing efforts on reducing the harm produced directly (e.g., overdose) and indirectly (exposure to infectious disease). Clonidine overdose
Naloxone can also be used as an antidote in overdose of clonidine, a medication that lowers blood pressure. Clonidine overdoses are of special relevance for children, in whom even small doses can cause significant harm. However, there is controversy regarding naloxones efficacy in treating the symptoms of clonidine overdose, namely slow heart rate, low blood pressure, and confusion/somnolence. Case reports that used doses of 0.1 mg/kg (maximum of 2 mg/dose) repeated every 1–2 minutes (10 mg total dose) have shown inconsistent benefit. As the doses used throughout the literature vary, it is difficult to form a conclusion regarding the benefit of naloxone in this setting. The mechanism for naloxones proposed benefit in clonidine overdose is unclear, but it has been suggested that endogenous opioid receptors mediate the sympathetic nervous system in the brain and elsewhere in the body. Some poison control centers recommend naloxone in the setting of clonidine overdose, including intravenous bolus doses of up to 10 mg naloxone. Preventing recreational opioid use
Naloxone is poorly absorbed when taken by mouth, so it is commonly combined with a number of oral opioid preparations, including buprenorphine and pentazocine, so that when taken by mouth, only the opioid has an effect. However, if the opioid and naloxone combination is injected, the naloxone blocks the effect of the opioid.
Animal models indicate that obesity causes leptin insensitivity in the hypothalamus, leading to decreased Kiss1 expression, which, in turn, alters the release of gonadotropin-releasing hormone (GnRH). Undiagnosed and untreated coeliac disease (CD). Coeliac men may have reversible infertility. Nevertheless, CD can present with several non-gastrointestinal symptoms that can involve nearly any organ system, even in the absence of gastrointestinal symptoms. Thus, the diagnosis may be missed, leading to a risk of long-term complications. In men, CD can reduce semen quality and cause immature secondary sex characteristics, hypogonadism and hyperprolactinaemia, which causes impotence and loss of libido. The giving of gluten free diet and correction of deficient dietary elements can lead to a return of fertility. It is likely that an effective evaluation for infertility would best include assessment for underlying celiac disease, both in men and women. Drugs, alcohol
Strenuous riding (bicycle riding, horseback riding)
Medications, including those that affect spermatogenesis such as chemotherapy, fluoxetine, anabolic steroids, cimetidine, spironolactone; those that decrease FSH levels such as phenytoin; those that decrease sperm motility such as sulfasalazine and nitrofurantoin
Genetic abnormalities such as a Robertsonian translocation

Tobacco smoking
There is increasing evidence that the harmful products of tobacco smoking may damage the testicles and kill sperm, but their effect on male fertility is not clear. Some governments require manufacturers to put warnings on packets. Smoking tobacco increases intake of cadmium, because the tobacco plant absorbs the metal. Cadmium, being chemically similar to zinc, may replace zinc in the DNA polymerase, which plays a critical role in sperm production.