Oral antibiotics are prescribed frequently for children for the treatment of such common bacterial infections as pharyngitis, tonsillitis, bronchitis, sinusitis and otitis media. These agents account for 30% of all medications prescribed by pediatricians.1 Many oral antibiotics have generic equivalents that are less expensive than their brandname counterparts. Acceptance of generic equivalents by prescribes and patients is increasing. The main factors determining acceptance of generic equivalent drugs by prescribers and patients include demonstration of their efficacy, potency, consistency, and cost advantages. To assist prescribers in the selection of high quality, cost-effective generic antibiotics, this article summarizes generic antibiotic utilization patterns, availability of generic oral antibiotics commonly used in the United States, and the regulatory process governing generic product approval. Palatability of selected products also will be addressed, as will the potential economic benefits attributable to generic product utilization.
GENERIC ANTIBIOTICS UTILIZATION PATTERN
Many commonly prescribed oral antibiotics have generic equivalents. Based on a 1994 survey of 71 health maintenance organizations (HMOs), generic antibiotics represented 66% of the oral antibiotic prescription volume and accounted for 26% of oral antibiotic expenditures.2,3 Penicillins, cephalosporins, macrolides, and trimethoprim/sulfonamide combinations are the most commonly prescribed types of oral antibiotics. As illustrated in Figure 1, 32% to 100% of these drugs are prescribed as generic equivalents.
Generic Availability of Oral Antibiotics Commonly Prescribed for Children
Figure 1. 1994 generic dollars and pharmacy prescription shares of oral antibiotics.2
Figure 2. 1995 generic compliance by specialties.
A recent study of a California HMO with 1 .35 million members compared the generic utilization rates among pediatricians, internists, obstetricians, and family practitioners. Pediatricians prescribed generic equivalents more often than any other group (Figure 2). This high utilization of generic equivalents by pediatricians was largely attributable to oral antibiotics commonly prescribed for pharyngitis, tonsillitis, bronchitis, sinusitis, and otitis media.
FOOD AND DRUG ADMINISTRATION (FDA) REGULATORY PROCESS
Concerns about the equivalency of generic products have been expressed for many years. The FDA considers drug products to be generic equivalents if they contain identical amounts of the same active ingrethent in the same dosage form and are identical in strength or concentration, and route of administration.4 Generic equivalents must be bioequivalent to the brand-name product and manufactured in compliance with current Good Manufacturing Practice regulations. Bioequivalence means that the generic equivalent is absorbed to the same extent and at the same rate as the name-brand product. Generic equivalents may differ from brand-name equivalents in shape, si2e, packaging, color, flavor, type of preservative, and expiration time.
Figure 3. 1995 correlation of generic compliance and pharmacy cost ($PMPM=cost per member per month).
The FDA categorized generic drugs into Category A or B. Category A products are considered to be therapeutically equivalent to other name-brand products for which there are either no known or suspected bioequivalence problems or any actual or potential bioequivalence problem has been resolved with adequate in vivo and in vitro evidence supporting bioequivalence. Category B products are those that are not bioequivalent. Most oral antibiotic generic equivalents fall into category A.4 In addition, oral antibiotics have a relatively wide margin of therapeutic and toxicity index. This wide range of safety and efficacy accommodates minor differences in bioequivalences (Table).
Another important consideration in the acceptability of oral antibiotics among children is palatability. The most cost-effective generic equivalent will not be of value if a child is unwilling to ingest the medication.5 Generic equivalents contain the same amount of active ingrethent as the brand name product, but may differ in shape, color, flavor, sweeteners, and preservatives. These differences may influence compliance. El-Chaar et al5 conducted a prospective, randomized, controlled, double-blind, crossover trial in which each patient served as his or her own control. Taste scores of cephalexin and erythromycin-sulfisoxazole generic products were not significantly different than their brand-name equivalents. The brand preparation of trimethoprim-sulfamethoxazole tasted significantly better than its generic counterpart. Despite the taste difference, compliance wirh the brand-name product and its generic counterpart were essentially identical. From the standpoint of palatability, a generic product does not generally taste worse than the brand-name product and should be prescribed to minimize health-care costs. Additional studies should be conducted to compare the palatability of all generic and brand-name products commonly used in children.
The management of pharmacy benefits is changing in parallel with the evolution of managed care. Generic substitution, formulary management, drug use evaluation, and prior authorization are the cost-containment strategies most commonly used by managed care health plans. Generic substitution was used in 87% of 71 managed care health plans in one survey.1 Some healdi plans encourage generic substitution by reimbursing pharmacies at a higher fee if generic products are dispensed. In addition, many insurance companies either reimburse patients for the cost of generic products only or require a higher copayment if brand-name medications are purchased.6
An analysis conducted at a large California HMO in 1995 demonstrated a significant correlation between their "per member per month" pharmacy cost ($PMPM) and the compliance rates with generic substitution: the average was $9.50 for those capitated medical groups with high generic compliance (≥50%) compared with an average of $11.50 in groups achieving ,45% generic compliance (Figure 3). Increased utilization of generic equivalents is associated with significant cost savings.
TOOLS TO IMPROVE GENERIC UTILIZATION
Brand-name products are dispensed if a practitioner specifies the brand name and specifically indicates, "no substitution." In general, brand names are more familiar to practitioners than generic names. However, if a brand-name product is written without further direction, the decision to dispense a generic equivalent can be made by the dispensing pharmacist. The relative profit to the pharmacy that derives from brand name versus generic substitution may influence what is dispensed. One way to assure increased utilization of generic products is to preprint prescription pads that state: "Dispense generic equivalents unless otherwise specified." Another way to ensure generic substitution is to adopt a written policy within a hospital or an integrated health-care delivery system.
The availability of generic products will become more limited in the near rature. The General Agreement on Tariffs and Trade (GATT) changed the term of patent protection from 1 7 years after the patent issue date to 20 years from the first application date and applied this extension to patents in force or applied for prior to June 8, 1995. As a result, approximately 110 pharmaceutical patents have been extended.7
Most oral antibiotics have highly acceptable generic equivalents. The generic products are comparable in bioavailability, side-effect profile, and efficacy to their brand-name equivalents. Some are more palatable, and all are less costly that the trade-name products. Increased use of oral generic antibiotics will generate significant cost savings for both the patients and prescribers, without compromising therapeutic benefits.
1. Fosarelli P, Wilson M, DeAngelis C. Prescription medications in infancy and early childhood. Am J Dis Child. 1987;141:772-5.
2. Emron 1994 HMO Prescription Drug Therapetic Class Report. Warren Townshlp, NJ: IMS Americani 1995.
3. Ramspacher S. Leading 1994 dollar volume pharmaceuticals. Hospital Pharmacy. 1995;30:666-669.
4. US Dept of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research. Approved Drug Products WiA Therapeutic Equivalence Evaluations. 16th ed. Rockville, Md: US Dept of Health and Human Services; 1996.
5. El-Chaar GM. Manly G1 Wehlou K, Rubin LG. Randomized, double-blind, comparison of brand and generic antibiotic, II: a study of taste and compliance in chil· dren. Pediatr Infect Dis J. 1996;15:18-22.
6. Nightingale SL. Morrison JC. Generic drugs and the prescribing physician. JAMA. 1987;258:1200-1204.
7. Betz R. Generic battle brand names over mortality of drug patents. J Healthcare Resource Management. 1995;13:35-7
Generic Availability of Oral Antibiotics Commonly Prescribed for Children