QUESTION: Dear sir,

My cousin aged was on atenolol 100 hctz 25 losartan 100 and amlosepine.

due bp increase his dr changed losartan 100 to olmesartan 40 mg. Is the new drug superior or rather 24 hours acting since he asked him to take olmesartan 40 mg in the night. Purpose of query is to ensure its efficacy since cost of olmesartan 40 is substantial.

secondly he asked to change atenolol 100 to metpure 50 xl wice ( (-) s metoprolol. Again it is slightly cost effective, i thought advisable to gave your views on this drug as to whether this will be really beneficial tomy cousin.

My intention is purely academic. I solicit your guidance since in India we do not have insurance for opd treatment and hence cost of medicines which need to be taken almost life long has a greater relevance.

Losartan is the prototype drug of its class while olmesartan is an advanced product, I agree that the cost is higher. Howver its advantages offset the cost.
Considering atenolol and metoprolol, I dont really feel the change was necessary.In any case I would make one change at a time, so that I can pin point which chqnge is usefull. If two changes are made, one cant say which was useful. It is unfortunate that most doctoers ignore the economics of medicines.
All the best.
Ravi Ghooi

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QUESTION: I acknowledge with gratitude your response. While we agree to your views, ki dly advise whether my cousin should take olmesartan 20 mg twice morning-night OR he should take olmesartan 40 mg once in night only. Regards

Olmesartan is a long acting drug with a terminal half life of around 13 hours against the 2 hour half life of losartan.
The effect of olmesartan therefore lasts for almost 24 hours, I would recommend a once a day usage of olmesartan. So your cousin may take 40 mg at night rather than taking 20 mg twice a day. Again depending upon how comfortable he is with the nightly dose, we may change if necessary.
All the best
Ravi Ghooi

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What is the difference between (-) S Metprolol and plain metoprolol. Is the dose of s-metprolol 50 is equal to plain metoprolol 100. I.e double to plain metoprolol?

I am  sorry for the delay in replying since I  was out of town attending meetings.
Many compounds exist in two forms and these are (-)S and (+)R. Mostly the (-)S form is biologically active  while (+)R is either not active or responsible for side effects. These two forms are sort of isomers but  known as chirals, separation  of these two requires  special techniques, and now a number of (-) S forms are  available in the market, these  include cetirizine, omeprazole, ranitidine and of course metoprolol etc.
Theoretically the (-)S should be  twice  as active  as the (+)R, but in biology 2 plus 2 is rarely 4, it  may be 3 or may be 5.
So while the (-)S form is usually better, it is difficult  to  say how much better it is, it is certainly more expensive.
Chiral chemistry is  difficult to understand and difficult to  explain, this should have won the Nobel prize but  the possibility of such isomers was shown over a 125 years ago by Louis Pasteur and hence it did not.
All the best
Ravi  Ghooi


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Dr. Ravindra Bhaskar Ghooi


I can provide information on drugs and medicines, their actions, uses, interactions and adverse effects. To avoid confusion, generic names of medicines may please be provided. I am a pharmacologist, having worked on animal and human pharmacology, and presently I am the Dean of Bilcare Research Academy, where we teach courses on clinical research. We dont work on saturdays and sundays, hence questions reachng me on these days will be replied on Monday, please bear with me.

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