Selecting The Cost Effective Antimicrobial : Quandary Of Medical Profession!

Rataboli P V, M.D. (Pharmacology) Assistant Professor, Dept. of Pharmacology Goa Medical College.Dang A, M.B.B.S, Post Graduate student Dept. of Pharmacology, Goa Medical College.Dang S, Senior Resident, Dept of Pediatrics ESI hospital, New Delhi.The name of the department to which the work is attributed: Dept. of Pharmacology, Goa Medical College, India.

Abstract

Background: Antimicrobial costs vary tremendously. It is difficult to make a decision whilst selecting a cost-effective antimicrobial in clinical practice. Prescribing costly antimicrobials can have a negative impact on patient’s compliance.
Aims: a) To compare the average retail price of different antimicrobials available in oral and parenteral dosage forms and calculate the cost of one day therapy. 2) To select and justify the use of certain antimicrobials as the most cost-effective in common microbial infections. Methods and materials: Pricelist of available antimicrobial brands was procured from IDR official site. Average price of commonly available oral and parenteral brands of antimicrobials was calculated. Cost of one day therapy was also calculated. Difference between oral and parenteral cost was observed.
Results and discussion: Study revealed that doxycycline and cotrimoxazole are the cheapest antimicrobials and ceftibuten is most expensive oral antimicrobial. Aztreonam is the most expensive parenteral antimicrobial in contrast to gentamicin which is the cheapest. A lot of take home messages and strategies are discussed. In general, parenteral dosage forms are more expensive than the oral dosage forms. The cost of one tablet is not directly proportional to the cost of therapy as the dosage of different antimicrobials vary. Long acting expensive drugs may ultimately end up being cheaper than the short acting counterparts. Costly antimicrobials need not be the better ones. Reducing the antimicrobial cost should remain our prime motive, and hence cost-effective antimicrobials should be selected, based on one’s knowledge , so that the drug costs are reduced while maintaining good quality of care.

Cost-effective antimicrobials, cost of therapy, oral and parenteral preparations.

Introduction
The cost of antimicrobials varies widely. Not only different antimicrobials cost differently but the same antimicrobial prices may vary vastly from one brand to another.(1) Although newer drugs are usually more expensive than older drugs, they are sometimes more effective than their older counterparts in reducing illness, hospitalization or death.(2) The improvements in healthcare outcomes can often justify the high costs.(3) Little information is available to doctors to determine which therapy works best(4) and very few studies have measured the cost benefits of new drugs.(2)

This study was undertaken to compare the average cost of one day therapy of various commonly available antimicrobials in general practice both for oral and parenteral use and to discuss the possible means of reduction of antimicrobial cost after duly comparing their price tags and considering their efficacy and safety in given conditions. The idea is to make physicians realize the importance of cost factor, as increased costs for better health outcomes can often have negative consequences – patients taking less than the recommended dose, saving medication for future use or taking a cheaper medicine of same chemical name, prescribed to the other person for a similar reason.(5),(6)

Material and Methods

The pricelist of the available antimicrobial brands was procured from IDR official site called IDRMedCLIK@MedCLIK.com. Different and widely prescribed brands of commonly used oral and parenteral antimicrobials were selected for this study. The average price for each antimicrobial dose was calculated by taking up to 20 brands of each antimicrobial wherever possible. The prices considered for calculation were inclusive of local taxes. The total cost of one day therapy was then calculated from the average price considering the standard recommended dosage schedule. In case of parenteral dose, the lower range of the dose was considered for calculation.

Results

Our study reveals that of the commonly available oral antimicrobial preparations, ceftibuten (400 mg OD) is the costliest therapy followed by linezolid (600 mg BD), costing approximately Rs. 222/- and Rs. 155/- daily respectively (Table/Fig 1). On the other hand, doxycycline and cotrimoxazole are the cheapest drugs costing approximately Rs. 2.50 daily followed by tetracycline (Rs. 3.30 daily). Cefetamet pivoxil (3rd generation oral cephalosporin) costs Rs. 90/- daily (500 mg BD). Moxifloxacin (400 mg OD) is the costliest fluoroquinolone therapy (Rs 70/- per day) whereas clarithromycin (250 mg BD) is the most expensive macrolide (Rs. 50/- daily approximately). The cost of aminopenicillins is generally low but the amoxycillin cost increases many fold in combination with clavulanic acid (more than Rs. 60/- per day). Most of the fluoroquinolones (except moxifloxacin) cost around Rs. 5/- to Rs. 12/- daily. The cost of macrolides (except clarithromycin) varies between Rs. 12/- to Rs. 15/- daily

(Table/Fig 2) compares the cost of parenteral antimicrobial preparations in common use. The cost of aztreonam (2 gm TDS) is approximately Rs. 2500/- daily followed by piperacillin (4 gm) and tazobactam (500 mg) combination, in TDS dosage schedule. Other costly parenteral antibimicrobials include cefpirome, teicoplanin, linezolid, piperacillin, ceftizoxime and netilmicin, all costing more than Rs. 500/- daily. Gentamicin is the least expensive parenteral antibiotic (Rs. 15/- daily) followed by ampicillin alone or in combination with cloxacillin. The cost of cefotaxime and lincomycin also turns out to be less than Rs. 100/- per day.

(Table/Fig 3) compares the oral and parenteral cost per day of a few antimicrobials where both forms are available. Generally the parenteral preparations are much more expensive than the oral forms. Parenteral cefuroxime costs six times more as compared to oral cefuroxime axetil.

Discussion

Which antimicrobial to use in practice is a matter of concern. Economical factors many a times prevents the practitioner to use a particular antimicrobial as he feels that the patient may not be able to afford the same. Our study reveals that doxycycline and cotrimoxazole are the cheapest drugs to use. Unfortunately the current indications for these two antimicrobials are limited. The practitioner therefore has no alternative but to prescribe costlier antimicrobials. Excellent knowledge of the spectrum of the antimicrobials and the possible organisms causing the infection are must to finally decide the antimicrobial.

The cost of one tablet is not directly proportional to the cost of therapy, as the dosage schedule is different for different antimicrobials. Thus although each tablet of cefuroxime axetil costs more than double the cost of cephalexin, the total cost of a day’s therapy of the former is just marginally higher than the latter. Similarly the average price of one lomefloxacin or ofloxacin tablet is more than thrice the average price of one capsule of amoxycillin 250 mg, but the cost of a day’s therapy of all the three drugs is almost the same.

The choice of the antimicrobial in a given condition should primarily be influenced by the ETC principles i.e. efficacy, toxicity and cost, in this order(7). If two agents are equally effective but have significantly different adverse event profile, the safe agent should be selected. However, if efficacy and toxicity are relatively equal, cost should be considered, as prescribing a cheaper drug will vastly improve the patient’s compliance.

Our study revealed following observations and take home messages:

1) Long acting expensive antimicrobials may ultimately end up being cheaper than the short acting counterpart. For example:
•Daily cost of once daily azithromycin is Rs. 15.32 in contrast to Rs. 12.76 of erythromycin given four times daily, however the total cost of azithromycin therapy (given for 3 days) is much less (Rs. 45.94) than the therapy cost of erythromycin (given for 5 days) which comes to more than Rs. 63/-.
•Although each tablet of ofloxacin is double the cost of ciprofloxacin, the total cost of ofloxacin 400 mg once daily (Rs. 11.27) is less than ciprofloxacin 500 mg BD (Rs. 12.38).
•The total cost of moxifloxacin therapy (400 mg OD) is much less than cefetamet pivoxil (500 mg BD), although the cost of one tablet of the former is Rs.25/- higher than the latter.
•Although the cost per dose of teicoplanin (200 mg OD) is Rs. 667/-, the total cost of one day therapy with vancomycin is Rs. 1330/- due to QID dosage.

2) Costly therapy need not always be a better therapy for treating any medical condition. For example:
•Commonly used time tested amoxycillin is much cheaper and effective than many other antimicrobials.(8)
•It will be ridiculous to use the highly costly aztreonam for gram negative infections where aminogycosides are equally effective. A possible chance of nephrotoxicity is not good enough excuse to routinely prescribe aztreonam which is five times costlier than the costliest aminoglycoside netilmicin and 165 times more expensive than the traditional and commonly used gentamicin.
•If P. aeruginosa is isolated, then piperacillin alone can be used with an aminoglycoside since in documented pseudomonas infection, tazobactam does not enhance the activity of piperacillin against this pathogen, but will increase the cost of therapy to great extent.(9)
•Cefpirome and cefepime are equally effective 4th generation cephalosporins(10),(11), but the cost of former is much more than latter.
•Cefuroxime axetil 250 mg BD (expensive; Rs. 46/- daily) is as effective as doxycycline 100 mg BD (Rs. 2.45 daily) in adults with acute exacerbation of chronic bronchitis.(12)
•Azithr