Skip to main content

The pharmacological implications of Smoking!

Over 4800 separate substances have been found in cigarette smoke, and the health risks of cigarette smoking are well documented. 
Cigarette smoke may interfere with both the action and metabolism of a wide range of medications, some of which are relevant to anesthetic practice. Central to this is the cytochrome P450 multi-enzyme system of which there are around 30 CYP enzymes responsible for drug metabolism. Polycyclic aromatic hydrocarbons (PACs) in cigarette smoke react with these enzymes, in general inducing them, thus affecting the metabolism of a number of drugs including paracetamol, codeine and theophylline. It is only the last whose dose is significantly affected. 

 In addition, PACs also have an effect on a membrane bound glycoprotein called uridine diphosphate-glucuronotransferase (UGT). UGT partially metabolises codeine and morphine as well as being involved in the glucuronidation of a number of drugs including NSAIDs, amytriptyline and temazepam. It has consistently been shown that smokers have an increased requirements for opiates in the postoperative period. 

 Smoking decreases the potency of aminosteroid muscle relaxants (vecuronium >rocuronium) and of interest, greater than 10 hours abstinence from cigarette smoking decreases atracurium requirements. 

 The incidence of postoperative nausea and vomiting is reduced in smokers as is, interestingly, the prevalence of ulcerative colitis.

Reference
Sweeney BP, Grayling M. Smoking and anesthesia: The pharmacological implications. Anaesthesia 2009; 64(2): 179-86
Labels:

Comments

Post a Comment

Popular posts from this blog

power injectable peripherally inserted central catheters

Clinical experience with power injectable peripherally inserted central catheters in intensive care patients     Introduction In intensive care units (ICU), peripherally inserted central catheters (PICC) may be an alternative option to standard central venous catheters, particularly in patients with coagulation disorders or at high risk for infection. Some limits of PICCs (such as low flow rates) may be overcome by the use of power-injectable catheters . Method We have retrospectively reviewed all the power injectable PICCs inserted in adult and pediatric patients in the ICU during a 12-month period, focusing on the rate of complications at insertion and during maintenance. Results We have collected 89 power injectable PICCs (in adults and in children), both multiple and single lumen. All insertions were successful. There were no major complications at insertion and no episodes of catheter-related blood stream infection. Non-infective complications ...
1 comment
Read more

Falling from Height...The Prognostic factors

Falls from Height is Knwon to cause major morbidities and mortalities.  There are several prognostic factors for survival that have been identified: Height Age Type of surface Body part that touches the ground first Two other factors are important, but do not have a significant effect on mortality: Circumstances of the fall (suicide, accident, escape) Initial impact with an object before impacting the ground Height . Overall, about half of victims die at the scene, and a total of 70% die before they reach the hospital . The median height leading to death is about 49 feet, or about 4 to 5 storeys. 100% of victims die after falling 85 feet, or about 8 storeys. Age . Mortality increases with age due to pre-existing medical conditions and decreased physiologic reserve. Type of surface . The type of surface struck (i.e. grass, water, construction debris) can also have an effect on secondary injuries and survival. Mortality after striking a hard surface is nearly doubl...
Post a Comment
Read more

The 12 decision making steps for post dural puncture headache treatment

Treatment decision-making algorithm for postdural puncture headache. 1. When diagnosis is made, all patients should receive supportive measures (reassurance, bed rest, analgesics, hydration, quiet environment). 2. Severity of symptoms should be classified using VAS scale (mild 1–3, moderate 4–6, severe 7–10). 3. Virtually all patients will improve in time even without additional therapy. (dashed lines) 4. Symptoms worsen or fail to resolve within 5 days. 5. Patient preference dictates the choice between pharmacologic (less effective) and epidural blood patch (EBP). 6. In patients with severe symptoms, EBP is strongly suggested. 7. The most common pharmacologic measure is  caffeine  prescription. 8. The failure, worsening, or recurrence of symptoms after pharmacologic measures favors the use of EBP. 9. In addition to EBP, other epidural treatment options can be considered in select patients (eg,  dextran , saline). 10. A period of 24 h should lapse before repeating EBP. 11...
1 comment
Read more