RSS
people

Know your alcohol units

alcohol units

One unit of alcohol is 10ml (1cl) by volume, or 8g by weight, of pure alcohol (patient.co.uk)

One hour is required to clear one unit of alcohol

Picture credit – bbc.co.uk

2 Comments | Tags: , ,

Alcohol and interactions

A friend asked me this today, try it.

Does alcohol affect any of these drugs?

Allopurinol, Amiodarone, Logynon, Warfarin, Methotrexate

Alcohol interactions

Eventhough alcohol interacts with a lot of drugs, but only several will have significant effect.

  • Antibacterial i.e. Metronidazole – disulfiram-like reaction
  • Anticoagulant i.e Coumarins, Phenindione
  • Antidepressants i.e. MAOi, TCA, Mirtazapine

I guess you know the answer now!

No Comments | Tags: , , , , ,

List of hepatic enzyme inducing drugs

I was looking through the new protocol for EHC(Emergency hormonal contraception) from the Torbay NHS Care Trust. I found something useful and worth sharing. It’s the list of  Hepatic Enzyme Inducing Drugs, I’v always wanted to come up with a list myself, but I just havn’t got to it. This group of drugs accelerates metabolism and reduces the efficacy of many drugs especially drugs with a narrow therapeutic window i.e theophylline, it is also important to know that they do the same for contraceptive steroids. I think the 1st few on the list are the more common List of hepatic enzyme inducing drugs .

  • Carbamazepine
  • Griseofulvin
  • Phenytoin
  • Rifampicin
  • St John’s Wort
  • Barbiturates
  • Modafinil
  • Topiramate
  • Primidone
  • Tacrolimus
  • Oxcarbazepine
  • Ritonavir
  • Rifabutin
  • Bosentan
  • Certain PPI
  • Certain HIV drugs

For me, I try to remember the 5 that are highlighted in red, to make it easier, I came up with an acronym – C-GPRS, hope that was helpful!! Leave a comment to add any others to the list!

4 Comments | Tags: , , ,

Oral contraceptives and their interactions

A question from my tutor prompt me to read up on oral contraceptives and their interactions. I’v always known there is some sort of interactions with antibiotics and with liver enzyme inducing drugs, however, what I knew probably wasn’t good enough to pass exams. Anyway here is just a recap/prompt for you to look it up and read more about it.

pill

 

Does flucloxacillin interacts with the combined oral contraceptive pill?

Does flucloxacillin suppresses the gut flora?

 

 

Main points are highlighted in RED.

Part ILiver Enzyme Inducing drugs i.e. Rifampicin (reduces effectiveness of oral contraceptives)

Short Course : Need to adjust pill to provide 50mcg ethinylestradiol or more daily, additional contraceptive protection, and continue for 4 weeks after stopping LEI drug.

Long-term Course : Consider contraceptive method not affected by liver enzymes, if no alternative, provide 5omcg ethynylestradiol or more daily, and tricycling recommended

*Tricycling - taking 3 or 4 packs of monophasic tabs without a break followed by 4 days pill free period.

Part IIAntibiotics that do not induce liver enzymes (reduce effectiveness of pill by imparing gut flora responsible for oestrogen recycling)

Additional protection required during Abx course, and continue for 7 days after completing Abx, if the 7 days run beyond the end of cycle, start next cycle immediately, for ED tabs, omit the inactive tabs.

* If Abx Tx more than 3 weeks, dont need additional protection due to bacterial resistance

List of Abx affected (non-enzyme inducing)

  • Rifampin (the only enzyme inducing antibiotic affecting pills)
  • Ampicillin
  • Sulfamethoxazole
  • Nitrofurantoin
  • Penicillin
  • Tetracycline
  • Amoxicillin
No Comments | Tags: , , , , , , ,

OTC treatment for athlete’s foot for someone on warfarin

Finally, after 9 long months working in the dispensary, I get to work on the counter for a bit. So I have learnt something new today, would like to share it with you, and also I think jotting it down can help me enhance my memory.

Scenario

atheletesA middle aged lady in her 50’s asked for some cream for athlete’s foot. So upon going through all the WHAMM (questioning of when, how, age, medication history etc), I found out she is on warfarin. As we all know warfarin interacts with an awful lot of medications. Many pharmacists prefers to refer them to the doctor instead of offering any products over the counter. So knowing that she wants some cream for athlete’s foot, and she is on warfarin, what would be the most appropriate cream for her??

Comments

daktarin-cream-15g daktarin-gold-cream-15gCanesten_Cream_50g

We all know that athlete’s foot is a fungal infection, so antifungal cream would treat it, but we have got several to choose from. One of my top recommendation would be Daktarin Gold (Ketoconazole 2% cream), other available creams are Daktarin cream (Miconazole) and Canestan cream (Clotrimazole 1%) or even Lamisil (Terbinafine). Forget about Lamisil because its too pricey. Upon checking Stockleys drug interactions and BNF (british national formulary), I found out that ketoconazole and miconazole (creams are absorbed into the bloodstream) both increases the plasma concentration of warfarin(thins the blood), which increases the risk of bleeding. So I offered Clotrimazole 1% cream (canestan).

Directions of use

Clean and dry feet, apply cream 2-3 times a day for at least 2 weeks, and up to 4 weeks. Many customers experience recurrent problems, an antifungal powder would be useful to prevent further infections. Powder can be sprinkled on shoes and socks, and if using it as a treatment, it should be sprinkled between toes, and all over the feet. It is advisable to also change stockings/socks daily for people who have recurrent fungal infections.

Hope this article was helpful for some of you.

1 Comment | Tags: , , , , , ,