A Drug A Day

careful, you'll get addicted


Rifampicin is part of the rifamycin group of antibiotics, and is used to treat a number of bacterial infections including TB, Legionnaire’s disease and leprosy. Typically used as a co-treatment in conjunction with other antibiotics, it can be used as a sole treatment for prevention of Haemophilus influenzae B and meningococcal disease for patients who have been exposed to the bacteria.

Rifampicin can cause hepatotoxicity, and so frequent liver function tests are recommended while on courses of this antibiotic. Measurements of liver enzymes and blood tests are suggested pre-treatment.

The drug functions through inhibition of the bacterial DNA-dependent RNA synthesis by inhibiting DNA-dependent RNA polymerase from functioning correctly.






Trimetazidine is used for the treatment of angina pectoris, and works as an anti-ischemic metabolic agent. The utilization of myocardial glucose improves through the inhibition of long-chain-3-ketacyl CoA thiolase activity, reducing fatty acid oxidation and stimulating the oxidation of glucose. High rates of fatty acid oxidation can be detrimental during spells of angina due to the possibility of sodium and calcium overload in the heart, causing exacerbation of ischemic injuries and a decrease in cardiac efficiency during reperfusion.

Trimetazidine can react with monamine oxidase inhibitors, but has a high safety and tolerability profile otherwise.




Lindane is a drug used for treatment of scabies and lice but has been withdrawn from the market in many western countries due to concerns over neurotoxicity involved with the drug. Lindane acts as an organochloride insecticide.

In countries where the drug has not been banned, Lindane is not recommended to be used as a first line therapy as it may cause neurotoxicity or bone marrow suppression, but has been approved as a second line treatment for head lice (pediculosis capitis), pubic lice (pediculosis pubis) or scabies in patients over 2 years of age.

Lindane is directly absorbed through the parasite’s exoskeleton/ova. The gamma-aminobutyric acid (GABA(1)) receptor/chloride ionophore complex is the primary site of action for lindane, and other insecticides such as endosulfan, and fipronil. Blockage of the GABA-gated chloride channel reduces neuronal inhibition, which leads to hyperexcitation of the central nervous system.

There are no known drug interactions with Lindane.



Temazepam is a benzodiazepine used for severe insomnia and debilitating sleep disorders. Temazepam works by increasing the affinity of gamma-aminobutyric acid for GABA receptors by binding to the benzodiazepine receptors. This results in skeletal muscle relaxation, sedation, ataxia, motor impairment and anxiolysis. The binding of the the GABA neurotransmitter then opens the Ca channel, causing the cell membrane to become hyperpolarised.

Temazepam dispensing is heavily regulated and varies from country to country. Overdosing on temazepam can cause increasing central nervous system effects such as respiratory depression, difficulty staying awake, hypotension, mental confusion, coma and death.

As with most benzodiazepines, physical dependence and addiction can occur and so ceasing of taking the medication can cause withdrawal symptoms similar to alcohol/barbiturate withdrawal.


Penciclovir is an anti-viral drug used for treatment of herpesvirus infections. Generally used as a topical treatment given that it is absorbed poorly when taken orally, penciclovir is an active ingredient in some cold-sore treatments.

Penciclovir works by inhibiting viral DNA polymerase and preventing the virus to replicate within cells.



Fenoterol is a short-acting beta 2 agonist which opens the airways to the lungs by decreasing bronchoconstriction. The stimulation of beta 2 receptors in the lungs causes the bronchial smooth muscle to relax, bronchodilation to occur and an increase in bronchial airflow.

Beta(2)-receptor stimulation in the lung causes relaxation of bronchial smooth muscle, bronchodilation, and increased bronchial airflow.

Fenoterol can be used to treat exacerbation of COPD as well as severe exacerbation of asthma symptoms.


Cevimeline works to alleviate symptoms of dry mouth associated with Sjögren’s syndrome. Cevimeline works as a cholinergic agonist binding to muscarinic receptors. As a muscarinic agonist, cevimeline binds and activates the muscarinic M1 and M3 receptors. M1 receptors are present in secretory glands, and the activation of these receptors results in an increase in secretions from the secretory glands. M3 receptors are found on smooth muscle  and many glands which aid stimulation of secretion in salivary glands, and so their activation will result in the contraction of smooth muscle and the increase of glandular secretions. As the excretion of saliva increases, the symptoms of dry mouth are alleviated.




Methadone is an opioid analgesic that functions as a mu-opioid agonist. Generally used for maintenance and detoxification treatment of narcotic addiction, methadone can also be used for severe pain relief and to control intractable coughs associated with terminal lung cancers.

Methadone offers a similar effect to that of morphine, but the onset of the drug is slower with less severe symptoms and a more prolonged course.

Overdosing of methadone can cause cardiac arrest, apnea and circulatory collapse, and can result in death, particularly if administered via intravenous route. Methadone is a controlled drug in most areas, and can only be administered by trained healthcare professionals such as pharmacists.



Cefapirin is an injectable cepahalosporin antibiotic, effective against gram negative & positive organisms.

The mechanism of action works by the inhibition of cell wall synthesis via the molecule’s affinity for Penicillin Binding Proteins (PBPs). Given this feature, Cefapirin tends to be more resistant to beta-lactamases than penicillins and so can be used for the treatment of staphylococci, except methicillin resistant staphylococci infections. Production of Cefapirin for humans has been discontinued in the US, but remains in use in the veterinary sector.

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