Osimertinib is an oral, third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) drug developed by AstraZeneca Pharmaceuticals. Its use is indicated for the treatment of metastatic non-small cell lung cancer (NSCLC) in cases where tumour EGFR expression is positive for the T790M mutation as detected by FDA-approved testing and which has progressed following therapy with a first-generation EGFR tyrosine kinase inhibitor. Approximately 10% of patients with NSCLC have a rapid and clinically effective response to EGFR-TKIs due to the presence of specific activating EGFR mutations within the tumour cells. More specifically, deletions around the LREA motif in exon 19 and exon 21 L858R point mutations are correlated with response to therapy. Osimertinib is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) that binds to certain mutant forms of EGFR (T790M, L858R, and exon 19 deletion) that predominate in non-small cell lung cancer (NSCLC) tumours following treatment with first-line EGFR-TKIs. As a third-generation tyrosine kinase inhibitor, osimertinib is specific for the gate-keeper T790M mutation which increases ATP binding activity to EGFR and results in poor prognosis for late-stage disease. Furthermore, osimertinib has been shown to spare wild-type EGFR during therapy, thereby reducing non-specific binding and limiting toxicity. Osimertinib is marketed under the brand name Tagrisso.

Febuxostat (ULORIC) is a novel, xanthine oxidase/dehydrogenase (XO/XDH) inhibitor being developed by Teijin, TAP Pharmaceuticals, and Ipsen for the treatment of gout. The currently available XO inhibitor, allopurinol, has been associated with serious instances of severe hypersensitivity, in some cases leading to fatalities. There is some suggestion that febuxostat is less prone to excacerbate systemic inflammatory events in animal studies. Febuxostat, a xanthine oxidase inhibitor, achieves its therapeutic effect by decreasing serum uric acid. Febuxostat is not expected to inhibit other enzymes involved in purine and pyrimidine synthesis and metabolism at therapeutic concentrations. Febuxostat is used for the treatment of hyperuricemia in patients with gout.

Daptomycin is a lipopeptide antibiotic used in the treatment of systemic and life-threatening infections caused by Gram-positive organisms. Daptomycin has a distinct mechanism of action, disrupting multiple aspects of bacterial cell membrane function. It inserts into the cell membrane in a phosphatidylglycerol-dependent fashion, where it then aggregates. The aggregation of daptomycin alters the curvature of the membrane, which creates holes that leak ions. This causes rapid depolarization, resulting in a loss of membrane potential leading to inhibition of protein, DNA, and RNA synthesis, which results in bacterial cell death. Daptomycin is bactericidal against Gram-positive bacteria only. It has proven in vitro activity against enterococci (including glycopeptide-resistant enterococci (GRE)), staphylococci (including methicillin-resistant Staphylococcus aureus), streptococci, corynebacteria and stationary-phase Borrelia burgdorferi persisters.

Linezolid is an antibiotic used for the treatment of infections caused by Gram-positive bacteria that are resistant to other antibiotics. Linezolid appears to be unique in that it blocks the initiation of protein production. Most common adverse reactions include diarrhea, vomiting, headache, nausea, and anemia. Linezolid has the potential for interaction with adrenergic and serotonergic agents. And with monoamine oxidase inhibitors because it’s nonselective inhibitor of monoamine oxidase.

Acyclovir is a synthetic antiviral nucleoside analogue. A screening program for antiviral drugs begun at Burroughs Wellcome in the 1960s resulted in the discovery of acyclovir in 1974. Preclinical investigation brought the drug to clinical trials in 1977 and the first form of the drug (topical) was available to physicians in 1982. Activity of acyclovir is greatest against herpes 1 and herpes 2, less against varicella zoster, still less against Epstein-Barr, and very little against cytomegalovirus. Acyclovir is an antiviral agent only after it is phosphorylated in infected cells by a viral-induced thymidine kinase. Acyclovir monophosphate is phosphorylated to diphosphate and triphosphate forms by cellular enzymes in the infected host cell where the drug is concentrated. Acyclovir triphosphate inactivates viral deoxyribonucleic acid polymerase.

Atenolol is a Beta-1 cardio-selective adreno-receptor blocking agent discovered and developed by ICI in 1976. Atenolol was launched in the market under the trade name Tenormin in 1976, and became the best-selling Beta-blocker in the world in the 1980s and 1990s. TENORMIN is indicated for the treatment of hypertension, to lower blood pressure; also for the long-term management of patients with angina pectoris and also is indicated in the management of hemodynamically stable patients with definite or suspected acute myocardial infarction to reduce cardiovascular mortality. Like metoprolol, atenolol competes with sympathomimetic neurotransmitters such as catecholamines for binding at beta(1)-adrenergic receptors in the heart and vascular smooth muscle, inhibiting sympathetic stimulation. This results in a reduction in resting heart rate, cardiac output, systolic and diastolic blood pressure, and reflex orthostatic hypotension. Higher doses of atenolol also competitively block beta(2)-adrenergic responses in the bronchial and vascular smooth muscles. Hypotensive mechanism of atenolol is very complex. Decrease in CO and inhibition of renin-angiotensin-aldosterone system may mainly be responsible for hypotension. It is likely that potassium retaining action of atenolol partly contributes to its hypotensive action. It is also hypothetized that renal kallikrein-kinin system may play a role in modulating the hypotensive action of atenolol.

Clindamycin phosphate is the prodrug of clindamycin with no antimicrobial activity in vitro but can be rapidly converted in vivo to the parent drug, clindamycin, by phosphatase ester hydrolysis. It is indicated in the treatment of serious infections caused by susceptible anaerobic bacteria: Lower respiratory tract infections including pneumonia, empyema, and lung abscess caused by anaerobes; Skin and skin structure infections; Gynecological infections including endometritis, nongonococcal tubo-ovarian abscess, pelvic cellulitis, and postsurgical vaginal cuff infection caused by susceptible anaerobes; Intra-abdominal infections; Septicemia; Bone and joint infections. Orally and parenterally administered clindamycin has been associated with severe colitis, which may end fatally. Abdominal pain, gastrointestinal disturbances, gram-negative folliculitis, eye pain and contact dermatitis have also been reported in association with the use of topical formulations of clindamycin. Clindamycin has been shown to have neuromuscular blocking properties that may enhance the action of other neuromuscular blocking agents

Azathioprine remains one of the most important and widely prescribed drugs for immunosuppression/immunomodulation in autoimmune disease over 30 years after its introduction. Azathioprine is licensed for the treatment of only a limited range of autoimmune disorders, which is probably a reflection on the age of the drug. Widening the license for a drug is both costly and time consuming, and it would make no commercial sense for manufacturers to do so, at this late stage of life, for azathioprine. However, azathioprine is now so well established as an immunomodulating drug in autoimmune disorders that it represents the gold standard by which other drugs are compared. Azathioprine is indicated as an adjunct for the prevention of rejection in renal homotransplantation. It is also indicated for the management of active rheumatoid arthritis to reduce signs and symptoms. The combined use of azathioprine tablets with disease modifying anti-rheumatic drugs (DMARDs) has not been studied for either added benefit or unexpected adverse effects. The use of azathioprine tablets with these agents cannot be recommended. Azathioprine is a pro-drug, converted in the body to the active metabolite 6-mercaptopurine. Azathioprine acts to inhibit purine synthesis necessary for the proliferation of cells, especially leukocytes and lymphocytes. It is a safe and effective drug used alone in certain autoimmune diseases, or in combination with other immunosuppressants in organ transplantation. Its most severe side effect is bone marrow suppression, and it should not be given in conjunction with purine analogues such as allopurinol. The enzyme thiopurine S-methyltransferase (TPMT) deactivates 6-mercaptopurine. Genetic polymorphisms of TPMT can lead to excessive drug toxicity, thus assay of serum TPMT may be useful to prevent this complication. Azathioprine is metabolized to 6-mercaptopurine (6-MP). Both compounds are rapidly eliminated from blood and are oxidized or methylated in erythrocytes and liver; no azathioprine or mercaptopurine is detectable in urine after 8 hours. Activation of 6-mercaptopurine occurs via hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and a series of multi-enzymatic processes involving kinases to form 6-thioguanine nucleotides (6-TGNs) as major metabolites.

Pentazocine is a synthetically prepared prototypical mixed agonist-antagonist narcotic (opioid analgesic) drug of the benzomorphan class of opioids used to treat moderate to moderately severe pain. Pentazocine is sold under several brand names, such as Fortral, Sosegon, Talwin NX. Pentazocine acts as an agonist of κ-opioid receptors and as an antagonist of μ-opioid receptors. This compound may exist as one of two enantiomers, named (+)-pentazocine and (−)-pentazocine. Side effects are similar to those of morphine, but pentazocine, due to its action at the kappa opioid receptor is more likely to invoke psychotomimetic effects. High dose may cause high blood pressure or high heart rate.

Sulfamethoxazole is a synthetic antibacterial drug,which is used in combination with trimethoprim (Bactrim, Septra) for the treatment or prevention of infections that are proven or strongly suspected to be caused by bacteria. Sulfamethoxazole acts by inhibiting folic acid synthesis via enzyme called dihydropteroate synthase.