Rx Note

Introduction In a community pharmacy setting, almost on a daily basis, we recommend oral antihistamine to our customers, which could be for prevention and treatment of symptoms in allergic rhinitis , allergic conjunctivitis, urticaria , or a variety of other allergic diseases. 1st and 2nd Generation As an overview, antihistamines can be classified into 1st and 2nd generation. This dichotomy was introduced in 1983 to indicate a major pharmacological difference between terfenadine and astemizole. Being less lipid soluble, the second generation antihistamines is thus believed to be less readily penetrated the blood brain barrier, and hence does not cause drowsiness. However, second generation antihistamines are still able to penetrate the blood brain barrier and may cause drowsiness (thought it rarely occurs). In fact, there are textbooks using the terminology of "less sedating antihistamines" to describe the second generation antihistamines, instead of "non-sedating antih...

Indications Unlike its use for treatment of cancer, methotrexate is administered as long-term, low-dose therapy, usually 7.5 to 25 mg weekly in rheumatoid arthritis and other disorders. Sometimes, it might be a good idea to have a discussion with patients to select a day for them to take this medication. It could be a Monday, since methotrexate starts with a "M", or it could be a Sunday, since patient is going to church in the morning. Method of Administration In terms of prandial advice , methotrexate should be taken with an empty stomach. Milk-rich foods may decrease its absorption. However, under management, Lexicomp did suggest to administer without regards to food , which is interesting to be take note of. Being an antineoplastic agent, methotrexate is categorized under NIOSH List of Antineoplastic and Other Hazardous Drugs in Healthcare Settings, 2016 Group 1. The 2.5 mg methotrexate tablet should not be cut or crushed in an unprotected environment. If a weekly dose...

Introduction Benign Prostatic Hyperplasia (BPH) is a histologic condition of proliferation of smooth muscle and epithelial cells in prostatic transition zone. The prevalence increases with age , affecting approximately 42% of men between the ages of 51 and 60 years and 82% of men between the ages of 71 and 80 years. BPH may progresses to benign prostatic enlargement (BPE) and subsequent bladder outlet obstruction (BOO), leading to lower urinary tract symptoms (LUTS). Lower tract urinary symptoms (LUTS) may include Storage symptoms : daytime frequency, urgency, nocturia and incontinence Voiding symptoms: weak stream, dribbling, dysuria, straining Symptoms can significantly impact quality of life. Complications include acute urinary retention, urinary tract infection, bladder calculi and renal insufficiency. Treatment Principles The severity of reported BPH symptoms guides selection of treatment. Validated severity and bother scores exist, such as the American Urological Association Sym...

Introduction The World Health Organization (WHO) classifies low bone mineral density (BMD) according to T-score as either osteoporosis or osteopenia ; these definitions only apply to BMD measurements taken at the lumbar spine, total hip or femoral neck. Normal = -1 or higher Osteopenia = Between -1 and -2.5 Osteoporosis = -2.5 or lower Osteoporosis occurs most commonly in postmenopausal women, men over 50 years, and in patients taking long-term oral corticosteroids (glucocorticoids). Definitions: The T-Score is the number of standard deviations by which a patient's BMD varies from the young adult mean for their sex , as measured by dual energy X-ray absorptiometry (DXA). The Z-Score is the number of standard deviations a person's BMD varies from the age- and sex-matched mean BMD . Z-scores are recommended for reporting BMD in premenopausal women, men younger than 50 years and children. Management Conservative management (i.e. lifestyle changes) Address inadequate calcium i...

Introduction In a dream, my lecturer was showing a long list of medications. He asked, do you know what is the most prominent drug interaction that you can identify. I tried my best but I could not recognize the drug name. He answered, it would be interaction with MONEY. Yes, it is bit off topic here. Drug Interactions Two or more drugs given at the same time can exert their effects independently or they can interact. Interactions may be beneficial or may cause you to experience an unexpected side effect or reduced efficacy. Drug-drug interactions can be broadly classified as being either pharmacokinetic or pharmacodynamic. Pharmacokinetic - occur when one drug alters the absorption, distribution, metabolism or excretion of another. Pharmacodynamic - might be due to competition at receptor sites or occur between drugs acting on the same physiological system. Potentially harmful drug interactions may occur in only a small number of patients, but the true incidence is often hard to es...

Introduction Statins are widely recognized as the first-line lipid-modifying therapy for reducing cardiovascular risk due to consistent results of numerous randomized primary and secondary prevention clinical trials. They achieve this by inhibiting the hydroxymethylglutaryl coenzyme A reductase (HMG-CoA reductase), which catalyses the first committed step of cholesterol synthesis in the liver. Statins are hepatoselective with extensive first-pass metabolism , which is advantageous because the liver is the main site of cholesterol synthesis, with extrahepatic sites synthesising essential cholesterol. NOTE: There is growing interest in their potential pleiotropic effects , which are actions unrelated or indirectly related to their effect on plasma LDL levels, such as anti-infammatory and antioxidant effects. Administration Time When advising patients on statin use, it is commonly recommended to take statins at night. However, this statement may not apply universally to all statins av...

Introduction For hypertension management in patients without comorbidities , recommended options in most guidelines include: ACE inhibitors - especially for nonblack patients and may reduce mortality ARBs - especially for nonblack patients but they may not reduce mortality and have limited data on comparative efficacy Calcium channel blockers - have limited data on mortality reduction Thiazide-type diuretics - shown to reduce mortality The drug of choice for hypertension in pregnancy is still methyldopa (first line) and labetalol (alternative first line) with nifedipine as second line. Methyldopa, oral 250 mg TDS, doubling every 48 hours (up to 1 g TDS) until BP well controlled. Labetalol, oral 100 mg BD, doubling every 48 hours (up to 400 mg BD) until BP well controlled. Nifedipine, oral 10 mg TDS, up to 20 mg TDS, when BP poorly controlled despite maximum doses of methyldopa ± labetalol. Beta Adrenoreceptor Antagonists Beta-blockers are a class of drugs that slow down the heart rat...