Video is up :)
Thursday, February 9, 2017
Fact of the day: Most common causes of non gonococcal urethritis
MCC of NGU in decreasing order are:
Structure and properties of poxviruses mnemonic
Hello!
So we will be learning about the structure and multiplication of poxviridae today from the mnemonic: “Pox is in a big box”
Excited?
Wednesday, February 8, 2017
Memory aid for urease positive organisms
Hailo!
Here's a little memory aid for urease positive organisms.
Here's a little memory aid for urease positive organisms.
Alcohol and Drug Interactions: 4th Part
Hii friends...
This is the last post in the series: Alcohol and Drug Interactions. The previous posts in this series were Disulfiram-like Reaction, 2nd Part, and 3rd Part.
With Warfarin
1. Binge drinking- Leads to inhibition of warfarin metabolism by CYP450 enzyme system. So it can precipitate warfarin toxicity with increased bleeding tendency in the body.
2. Chronic Alcohol consumption- Leads to induction of CYP450 enzyme system, so increases metabolism of Warfarin in the liver. So higher than usual dose of warfarin is needed to exert appropriate anticoagulant action in the patient.
With Opioids
Alcohol increases the sedative effects and also increases the risk of respiratory depression. It also attenuates cough reflex and gag reflex, so the patients have a higher risk of getting food stuck in their respiratory tract, remember Cafe Coronary.
With NSAIDs
1. NSAIDs have been implicated in an increased risk of ulcers and gastrointestinal bleeding in elderly
people. Alcohol may exacerbate that risk by enhancing the ability of these medications to damage the
stomach mucosa.
2. Alcohol also potentiates the antiplatelet actions of Aspirin, hence increase the risk of bleeding in the patients.
3. Intake of alcohol with acetaminophen can increase the risk of acetaminophen-related toxic effects
on the liver. Acetaminophen breakdown by CYP2E1 (and possibly CYP3A) results in the formation of a toxic product(NABQI) that can cause potentially life-threatening liver damage. As mentioned earlier, heavy alcohol use enhances CYP2E1 activity. In turn, enhanced CYP2E1 activity increases
the formation of the toxic acetaminophen product. In people who drink heavily or who are fasting
(which also increases CYP2E1 activity), liver injury may occur at doses as low as 2 to 4 grams per day.
That concludes this series. I hope it will help you to guide your patients towards drinking alcohol more judiciously. :p
-VM
Alcohol and drug interactions: 3rd part
Hey, guys.....
This is the third post in the series, Alcohol and drug interactions. The other posts are Disulfiram-like Reaction, 2nd Part and 4th Part.
With Antihistaminics
Alcohol increases the risk of sedation, drowsiness and falls, especially in the elderly population and with the 1st gen antihistaminics.
With Barbiturates and Benzodiazepines
Alcohol acts synergistically with them to increase their sedative effects and memory-impairing effects( This memory-impairing effect is misused in Date Rape drug, Flunitrazepam(Rohypnol)). Besides it also inhibits their metabolism in the liver, hence, increasing the drug's levels in the blood.
With H2-Receptor Antagonists
These agents(eg., Cimetidine, Ranitidine) inhibit the action of Alcohol dehydrogenase(ADH) present in gastric mucosa. Cimetidine may also increase the rate of gastric emptying hence increasing the absorption of alcohol. So both of these effects contribute to increasing the Blood Alcohol levels.
With Muscle Relaxants
Several muscle relaxants (e.g., carisoprodol, cyclobenzaprine, and baclofen), when taken with alcohol, may produce a certain narcotic-like reaction that includes extreme weakness,
dizziness, agitation, euphoria, and confusion. For example, carisoprodol is a commonly abused and readily available prescription medication that is sold as a street drug. Its metabolism in the liver generates an anxiety-reducing agent that was previously marketed as a controlled substance (meprobamate). The mixture of carisoprodol with beer is popular among street abusers for creating a quick state of euphoria.
That's all!
-VM
Alcohol and Drug Interactions: 2nd part
Hey guys,
This is a continuation of the previous post on Disulfiram-like Reaction.
Let us start with a basic info. Pharmacokinetic drug interactions with alcohol are only seen in heavy drinkers whereas Pharmacodynamic drug interactions can be seen in moderate drinkers and even after a single episode of drinking.
With Antibiotics
As already mentioned, the Disulfiram-like reaction can occur with Isoniazid, Cefotetan, Cefamandole, Cefoperazone, Chloramphenicol, Sulfamethoxazole, Sulfisoxazole.
Besides patients on Isoniazid should abstain from drinking alcohol since isoniazid is hepatotoxic and the liver damage can be exacerbated by concurrent alcohol consumption
With Antidepressants
1. With TCAs: Alcohol increases the sedative action of TCAs, especially Amitriptyline, Doxepin etc.
Alcohol also impairs the first-pass metabolism of Amitriptyline in the liver causing increased bioavailability of the drug. Excessive increase in levels of TCAs in the blood can precipitate convulsions and cardiac arrhythmias.
2. Among SSRIs, all are relatively safer with alcohol; the safest being Fluoxetine.
3. With MAOIs(eg., Phenelzine, Tranylcypromine): There can be severe high BP(cheese reaction) if taken together with red wine which contains Tyramine.
That's all! :)
Do go through the subsequent posts in this series, 3rd Part and 4th Part.
-VM
Alcohol and Drug Interactions: Disulfiram-like Reaction
Hey, guys...
So day before yesterday, there was my Forensic Medicine viva and the examiner asked me the causes of impotency. And I immediately started blabbing about Stress, Phimosis, Hypospadias, Peyronie's disease, I even mentioned Parkinson's disease. The examiner interjected me and asked the most common cause. I guessed heart disease and the related medications and he denied. Then he said it is excess consumption of alcohol and asked me not to underestimate alcohol and it's various interactions and correlations ever.
So here I am, trying to summarize the interactions of alcohol with the major classes of drugs.
Disulfiram-like Reaction
I am not going to go into the details of the mechanism. Just, in brief, Disulfiram-like reactions entails flushing(due to dilatation of blood vessels), nausea, vomiting, sweating, hypotension, so reflex tachycardia which can be deleterious to a patient of coronary artery disease(CAD).
Now let us try to use CAD as a mnemonic here while learning certain other things as well.
1. It starts with C, a lot of drugs starting with C have this reaction, like Cefamandole, Cefoperazone, Cefotetan, Chloramphenicol.
2. Patients with CAD have Pain, so let us now manage that some analgesics starting with P(for Pain), Phenylbutazone, Phenacetin.
3. Patients with CAD can have attacks of Angina, for which we give Nitrates, so let us take that. Drugs with Nitro group: Nitroglycerin, Isosorbide dinitrate, Nitrofurantoin, Metronidazole. Why leave Sulpha group behind?
Drugs with Sulpha group: Sulphamethoxazole, Sulfisoxazole.
4. CAD often co-exists with Diabetes Mellitus(DM). So let us manage that with some Sulfonylureas; Tolbutamide, Tolazamide, Chlorpropamide and even the 2nd gen drug Glyburide.
5. Patients with DM are immunosuppressed. Hence, they are predisposed to Mycoses and TB. Manage them with Griseofulvin and Isoniazid respectively.
That's all! :)
Do go through the other posts in this series, 2nd Part, 3rd Part, and 4th Part
-VM
Tuesday, February 7, 2017
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