The extent of price variation amongst branded antihypertensive drugs and its association with number of pharmaceutical companies

INTRODUCTION

In the world, the estimated total number of people with hypertension was 972 million in 2000. It was predicted that in 2025 the number of adults with hypertension will reach to a total of 1.56 billion.¹ A great portion of this increased population of hypertension will be contributed by developing countries like India. In developed countries, prevalence of hypertension is stable or decreased. ² As per the WHO 2008 estimates, the prevalence of hypertension in Indians was 32.5% (33.2% in men and 31.7% in women).³ After being diagnosed, most of the hypertensive persons have to take antihypertensive drugs for life long. The cost of antihypertensive drugs can be reduced by selecting economical options for the benefit of common people without compromising the quality of treatment.⁴ The same medicine may differ in terms of price depending on brand, place and type of clinic/hospital. A study showed that the cost of antihypertensive drugs was about five to six times higher in the private hospitals/stores than at the government owned medical stores.⁵ Rational therapeutics is the amalgamation of right decisions. This includes choosing right drug, dosage form, and dose at the right cost. In the developing countries including India the main hindrance in proper treatment is the financial aspects of therapy. Many advisory committees have been formed regarding the recommendations of using generic drugs in place of branded to reduce the cost. Sometimes it becomes mandatory to prescribe drug by trade name due to bioequivalence factors involvement. The diseases where a narrow range of therapeutic outcomes are to be achieved the clinicians don’t take chance to prescribe a drug formulation which may have alerted bioequivalence. To minimize the inter drug formulation variations the clinicians rely on the branded drug for the treatment of diseases like hypertension, diabetes, epilepsy, stroke, cancer, etc. Physicians often ignore the price variations among the branded drugs of same compound of same strength. This ignorance is one of the causes for irrational therapeutics. To make the prescription rational the physicians should be aware of prize variations among the prescribed drugs. Whenever one writes a prescription he/she has to take 360⁰ consideration including the overall cost of the drug. Several studies have been done to compare the price variation among the generic versus branded medicine of same compound, however no scientific study has been done to compare the branded drugs regarding their price variation. Selection of P drug by clinicians is influenced by multiple factors including the personal experience, the advertisement policy of the drug company and other hidden unexplained favours or conflict of interest of physicians.⁶ Every time the selection of P dug may not be appropriate due to lack of knowledge of price of the to be selected drug and cost-effectiveness analysis of drugs is seldom available.⁷ A large price gap usually exists between branded and generic drugs and even the branded drugs may have remarkable variations in prices. So the selection should be based on basis of all pharmacological and economical factors. A lot has been discussed about generic versus branded drugs. Generic drugs usually cost a fraction of branded but sometimes physicians are suspicious about their quality. Cost of the treatment can also be down regulated by choosing branded drugs that are on the lower spectrum of price. The average monthly cost of antihypertensive drugs ranges between US $0.8 and US $6.6.⁸ The present article is about the cost effectiveness of choosing a drug depending on its position over the price spectrum.

METHODS

The present study was of descriptive type. Required information was obtained from the authentic sources including Drug today, CIMS (current index of medical specialities) and refRx. According to price, several brands of a particular drug used in management of hypertension are arranged on a spectrum and various parameters were observed.

1). Difference in maximum and minimum price for the same drug in same strength and dosage among various brands (absolute number as well as percentage). and 2). Difference in treatment cost between two ends of spectrum.

This study is not to promote or highlight any particular brand or company so brand/company names are not mentioned in the study.

Statistical analysis was done with the help of word excel. The formula for percentage variation in price was adopted from previous studies.⁹ The formula is as follows.

The percentage variation in price =

Price of most expensive brand - Price of least expensive brand / Price of least expensive brand x 100

The drugs were classified into nine categories depending on the percentage (%) range of price variation, which were as follows:¹⁰

• 1) 0-50%
• 2) 51-100%
• 3) 101-150%
• 4) 151-200%
• 5) 201-250%
• 6) 251-300%
• 7) 301-350%
• 8) 351-400%
• 9) >400%

RESULTS

A total of 116 formulations from different companies represented 38 antihypertensive drugs. All these were evaluated on price spectrum. The formulations whose price was not mentioned in books were excluded from the study.

The drugs manufactured/marketed by large number of companies are found to have high % price variation (Figure 1). Amlodipine formulations dominate amongst calcium channel blockers (Table 1). Four formulations of amlodipine are manufactured by more than fifty pharmaceutical companies. Some of the pharmaceuticals manufacture only single strength of amlodipine while many are manufacturing more than one strength. Percentage price variation ranges from 500% to 962.5%. Maximum variation is shown by 10 mg tablets on the other hand 7.5 mg preparation of amlodipine.

Among ACE inhibitors, ramipril is most commonly manufactured and is available in 4 formulations by 89 companies. Maximum price variation is seen with 5 mg dose of enalapril (Table 2).

Among ARBs, losartan is most commonly manufactured i.e., by 62 (25 mg by 28 companies and 50 mg by 34 companies) Maximum price variation (494.2%) is seen with 80 mg dose of valsartan (Table 3).

Among diuretics, torsemide is most commonly manufactured and is available in 6 formulations. Maximum price variation (210.71%) is seen with 2.5 mg dose of indapamide (Table 4).

Among β-blockers, atenolol is most commonly manufactured i.e., by 64 (50 mg by 28 companies, 25 mg by 19 companies and 100mg by 17 companies). Maximum price variation (3233.33%) is seen with 10 mg dose of propranolol (Table 5). Among alpha blockers, highest price variation (131.66%) is seen with 1 mg dose of terazocin. Phenoxybenzamine and phentolamine are not shown in drug today though these are preferred drugs for hypertensive crisis in pheochromocytoma (Table 6). Central sympatholytics drugs were manufactured by very few companies (Table 7).

DISCUSSION

We are living in an era of drug explosion. It is to be expected that more than lacs of medicinal formulations comprising of thousands of active ingredients are being marketed. Drug regulating authorities have emphasized a lot on quality and safety. Developing countries including India require medications at affordable prices for the benefit of masses. Most of the pharmaceuticals try to compensate the investments within a very short period without considering the financial status of the patients’ population.

In India NPPA (National Pharmaceuticals Pricing Authority) under the control of ministry of Chemicals and Fertilizers, was set up in 1997 to control drug pricing.

The main aim of this authority is to restrict/control the price of new as well as old medicines and to discourage the pharmaceuticals for taking undue profits. Indirectly this authority is playing a very important role in rational therapeutics. As per DPCO (Drugs Prices Control Order), a ceiling price is fixed for each scheduled formulation and the medicine cannot be sold at an MRP exceeding the ceiling price plus applicable local taxes.

In present study the price variation among β blockers was appreciably high (>3000%, lowest price was Rs. 0.3/tablet and highest price was Rs. 10/tablet). Second highest price variation (of 962%) is seen with amlodipine 10mg tablet and third highest price variation (of 879%) is also seen with amlodipine (5 mg tablet).

Some of the formulations were manufactured by only single company. The reason for this may be less requirement of a particular drug or particular formulation/strength. Surprisingly we found that labetalol 200mg formulation which is manufactured by single company is costing less as compared to 100mg strength. We couldn’t hypothesize the cause for this price discrepancy. Logically it is expected that the company which formulates single preparation without competitors keep the price slightly high showing its monopoly. But the case of labetalol is just the opposite.

On the other hand captopril 12.5 mg was costing more (manufactured by single pharmaceutical company) than its counterpart strength 25 mg (manufactured by multiple pharmaceutical companies). Similar price discrepancy is seen in case of valsartan 40mg as compared to valsartan 80mg. this discrepancy is one of the most important point which we want to highlight. The price regulation authorities should take these types of price variation into consideration and ask the explanations from pharmaceuticals companies.

CONCLUSION

Indian pharmaceutical companies are well known in the world for providing drugs at very low cost. At the same time there is huge price variation among some formulations and by considering this fact, cost of treatment can be further reduced. By creating awareness among doctors and pharmacists about various methods of drug cost reduction, monetary burden of diseases (especially chronic) can be reduced in other parts of the world also.

ACKNOWLEDGEMENTS

The authors thank Assistant Professor Sarvesh Singh and Assistant Professor Narendra Kumar for their feedback and helping attitude throughout the study. No funding was obtained for this study and authors had no conflicts of interest. Authors’ acknowledge the help provided from the books including Drug Today, CIMS, refrx.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the Institutional Ethics Committee

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