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

Things to Avoid in Anesthesia for Pregnant with Pulmonary hypertension

Anesthesia for Pregnant woman with Pulmonary Hypertension is a real challenge for anesthesiologist. It is very crucial to remember the pathophysiology of pulmonary hypertension in pregnant women and to avoid some practices that will worsen the cardiac status. 1-Avoid single shot spinal anesthesia. Some authorities consider pulmonary hypertension as absolute contraindication for single shot spinal anesthesia specially in patients with NYHA III ,IV. Spinal anesthesia causes major hemodynamic instability(decrease SVR, decrease VR, decrease in CO) The preferred neuroaxial techniques are (epidural anesthesia and CSE with minimal spinal dose) 2-Avoid PAC. Pulmonary Artery catheters insertion may lead to pulmonary artery rupture or thrombosis. TEE is better cardiac monitor/Arteial line is mandatory. 3-Avoid Nitrous oxide in gas mixture.N2O increase the PVR 4-If MV to be started, avoid High TV and PEEP 5-Avoid Oxytocin Boluses, or rapid administration of Pitocin. Oxytocin causes ...
Post a Comment
Read more

Steroids In Perioperative period...The Multi-purpose Drugs

1-Steroids are not Bronchodilator ,but have well established usefulness in hyper-reactive airway. They are also said to have a permissive role for bronchodilator medication. They can be administered orally, parenterally or in aerosol form 2- Steroids have been commonly used in chemotherapy for prevention of nausea along with other anti-emetic agents . Dexamethasone was found to be highly effective when given immediately before induction rather than at the end of anesthesia . 3- Steroids do exert analgesic effects. Various routes of administration of steroids include parentral, local infiltration at operated site , as an adjuvant in nerve blocks and central-neuraxial blockade. 4 - Steroids cannot be the mainstay of therapy in anaphylaxis because of the delayed onset of action, so they are used as adjunct after initial treatment with epinephrine. 5- Steroids (Dexamethsone) are of value in reduction or prevention of cerebral edema associated with parasitic infections and neopla...
1 comment
Read more