Category Archives: Internal Medicine

Benzodiazepines mechanism of action

Benzodiazepines and GABA receptors: an animation on their mechanism of action

Gamma amino butyric acid (GABA) is an inhibiting neurotransmitter that is present on human brains. As shown in the animation, gamma amino butyric acid promotes opening of a postsynaptic receptor, the GABA-A receptor.

This opening leads to a increased conductance to cloride ions, which produces membrane hiperpolarization, this induces a neuronal inhibition.

The binding of benzodiazepines to the GABA-A receptor increases the affinity of gamma amino butyric acid (GABA) and its receptor, thereby increasing the opening frecuency of GABA-A receptor.As a consequence of this, benzodiazepines potentiate GABAergic neurotransmission.

Drug list:

Some of the drugs included under the benzodiazepine class are:

  • Alprazolam
  • Diazepam
  • Flurazepam
  • Lorazepam
  • Midazolam
  • Oxazepam
  • Prazepam
  • Temazepam
  • Triazolam

References:

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  • Modern Pharmacology with Clinical Applications, Sixth Edition by Charles Craig
  • Principles of Pharmacology: The Pathophysiologic Basis of Drug Therapy, Second Edition
    by David E Golan

Clinical guidelines on pneumonia management and treatment

This post features two clinical guidelines on the management of community acquired pneumonia.

The British Thoracic Society updated this year many recommendations, including when to order a chest X-ray, and antibiotic management.

The guidelines issued by the Infectious Diseases Society of America and the AmericanThoracic Society have relevant recommendations concerning empirical antimicrobial therapy and its duration.Continue Reading

Medwatch alert. Topical anesthetics: risk of cardiologic and neurologic side effects

FDA issued a safety warning about the hazards of topical anesthetics [Posted 01/16/2009] FDA issued a public health advisory to remind patients, healthcare professionals, and caregivers about potentially serious hazards of using skin numbing products, also known as topical anesthetics, for relieving pain from mammography and other medical tests and conditions. FDA is concerned about…

Aliskiren (Rasilez) for essential hypertension: not recommended by the NHS Scotland

The Scottish Medicines Consortium issued on 5th December 2008 an advice on aliskiren (Rasilez, Tekturna in the US): Aliskiren (Rasilez) is not recommended for use within NHS Scotland for the treatment of essential hypertension. Aliskiren has shown comparable efficacy to other antihypertensive agents in terms of blood pressure reduction, though its effects on mortality and…Continue Reading

Sitaxentan (Thelin) for pulmonary hypertension. Australian Prescriber review

From Australian Prescriber: Sitaxentan sodium Thelin (CSL) 100 mg tablets Approved indication: pulmonary hypertension Australian Medicines Handbook section 6.7.2 Pulmonary hypertension results from intimal hypertrophy narrowing small pulmonary arteries. The increase in pulmonary vascular resistance leads to right ventricular failure. Primary pulmonary hypertension is less common than the pulmonary hypertension associated with other conditions such…Continue Reading

Panitumumab (Vectibix) for metastatic colorectal carcinoma. Australian Prescriber review

From Australian Prescriber: Panitumumab Vectibix (Amgen) vials containing 20 mg/mL in 5 mL, 10 mL or 20 mL volume Approved indication: metastatic colorectal carcinoma Australian Medicines Handbook section 14.2.1 Panitumumab is a humanised monoclonal antibody for the treatment of metastatic colorectal carcinomas expressing the epidermal growth factor receptor. It is indicated for patients whose tumours…Continue Reading

Pharmacological efficacy and safety. Clinical therapeutic index definition.

The following pharmacological definition has been taken from the Pharmacology and Experimental Therapeutics Department Glossary at Boston University School of Medicine. Clinical Therapeutic Index: Some indices of relative safety or relative effectiveness cannot be defined explicitly and uniquely, although it is presumed that the same quantifiable and precise criteria of efficacy and safety will be…Continue Reading

Alfuzosin does not improve symptoms of chronic prostatitis- chronic pelvic pain syndrome

From JournalWatch: Alpha-Blocker Does Not Ease Symptoms of Chronic Prostatitis Alfuzosin, an alpha-adrenergic–receptor blocker, does not improve symptoms in men with chronic prostatitis–chronic pelvic pain syndrome, according to a New England Journal of Medicine study.Continue Reading

CHMP positive opinion for lasofoxifene (Fablyn), a new SERM

Press release about the positive opinion of the CHMP for Fablyn (lasofoxifene): COMMITTEE FOR MEDICINAL PRODUCTS FOR HUMAN USE  SUMMARY OF POSITIVE OPINION for FABLYN International Nonproprietary Name (INN): lasofoxifene On 18 December 2008  the Committee for Medicinal Products  for Human Use (CHMP) adopted a positive opinion, recommending to grant a marketing authorisation for the…Continue Reading

EMEA positive opinion for prasugrel (Efient)

Press release about the positive opinion of the CHMP for the antiplatelet agent Efient (prasugrel): COMMITTEE FOR MEDICINAL PRODUCTS FOR HUMAN USE SUMMARY OF POSITIVE OPINION for EFIENT International Nonproprietary Name (INN): prasugrel On 18 December 2008  the Committee for Medicinal Products  for Human Use (CHMP) adopted a positive opinion, recommending to grant a marketing…Continue Reading

Antiepileptic drugs (AEDs): FDA requires warnings about suicidal thoughts and behaviors (suicidality)

The FDA will require manufacturers of antiepileptic drugs (AEDs) to inclued a warning about the increased risk of suicidal thoughts and behaviours when using these drugs. This is a transcript of the original press release dated Dec. 16, 2008: FDA Requires Warnings about Risk of Suicidal Thoughts and Behavior for Antiepileptic Medications The U.S. Food…Continue Reading

An FDA advisory panel voted to ban formoterol (Serevent) and salmeterol (Foradil)

From JournalWatch: FDA Panel Votes to Ban Two Drugs for Asthma An advisory panel to the FDA voted Thursday to ban two long-acting beta agonists, Serevent (salmeterol) and Foradil (formoterol), for treating asthma in adults and children. When taken without an inhaled corticosteroid, these drugs canContinue Reading

NSAIDS risks and benefits podcast

This week Therapeutics initative podcast deals with NSAIDS: NSAIDS: Considering the Risks and Benefits (Therapeutics Initiative Podcast – December 10th) In our 33rd episode we follow-up our discussion of osteoarthritis by examining the risks and benefits of oral anti-inflammatories including Cox-2 inhibitors. We review the effects on pain relief and the theory of anti-inflammation. We…Continue Reading

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