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U.S. Department of Health and Human Services

Animal & Veterinary

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FDA Veterinarian Newsletter March/April 1999 Volume XIV, No II

Many of the narcotics, depressants, and stimulants manufactured for legitimate medical uses are subject to abuse, and have therefore been brought under legal control. The goal of controls is to ensure that these "controlled substances" are readily available for medical use, while preventing their distribution for illicit sale and abuse. On October 27, 1970, Congress passed the Comprehensive Drug Abuse Prevention and Control Act. Title II of the Act, known as the Controlled Substances Act (CSA), gave the Department of Justice the authority to regulate commerce of drugs of abuse. The CSA is administered by the Drug Enforcement Administration (DEA), which is the lead Federal agency for the enforcement of narcotics and controlled substance laws and regulations.

The CSA established five schedules that classify controlled substances according to their potential for abuse. Drugs are placed into categories according to how dangerous they are, how great their potential for abuse is, and whether they have any legitimate medical value.

Regulations for prescribing controlled substances are included in Title 21, Part 1306 of the Code of Federal Regulations (CFR). These regulations state that:

  • No prescription for a controlled substance may be issued unless there is a legitimate medical reason.
  • Narcotics under any schedule may not be prescribed for "detoxification" or "maintenance treatment."
  • Prescribing practitioners as well as the pharmacists who fill the prescriptions, share the corresponding responsibilities to adhere to the laws and regulations of the Food and Drug Administration (FDA), DEA, the States in which they are practicing, and their licensing boards.
  • In the event that discrepancies between Federal and State laws exist, the more stringent of the two must be followed.

Information about products in these schedules and prescribing restrictions follows.

Schedule I Products

The Food and Drug Administration (FDA) and the DEA have not recognized any legitimate medical purpose for such controlled substances. Examples of Schedule I products are heroin and marihuana. Issuance of prescriptions for Schedule I products is prohibited.

Schedule II Products

Examples of Schedule II products which are approved for use in animals include pentobarbital, oxymorphone, naloxone, fentanyl, butorphanol, and secobarbital. Except for butorphanol, which is available in both tablet and injectable form, all other Schedule II drugs are injectables. FDA has no evidence that these animal drug products are used illicitly.

Physical and psychological dependence on most of the Schedule II drugs is high, and normally results in withdrawal symptoms. Therefore, production of these drugs is controlled by DEA. FDA determines and advises DEA on whether production of these products needs to be curtailed or increased depending upon medical needs. FDA's Center for Veterinary Medicine (CVM) and Center for Drug Evaluation and Research (CDER) collaborate in this decision-making process. Refillingof prescriptions for Schedule II products is prohibited under Title 21, Part 1306.12 of the CFR.

Schedule III Products

Examples of Schedule III products include androgenic anabolic agents, such as boldenone, testosterone, and stanozolol. Since these drugs are formulated in both injectable and tablet dosage forms and have potential for abuse, they have not been exempted from CSA. Anabolic agents which are used as implants are unlikely to be abused, and therefore are exempted from Schedule II requirements of CSA. An example of these types of drugs is trenbolone acetate which is chemically and pharmacologically related to testosterone and defined as a controlled substance under Title 21, Part 1300.01(a)(4) of the CFR. Since it is only approved as an implant, trenbolone acetate is exempted from CSA requirements.

Schedule IV Products

Examples of Schedule IV products are benzodiazepines such as barbital, clonazepam, diazepam (Valium), and diethylpropion.

Under Title 21, Part 1306.22 of the CFR, no prescription for a controlled substance listed in Schedule III or IV may be filled or refilled more than six months after the date on which such prescription was issued, and no such prescription may be refilled more than five times.

Schedule V Products

Examples of Schedule V products include buprenorphine, cough syrup containing codeine, and lomotil. Although codeine is a Schedule II drug, the concentration permitted in cough syrup is low enough to classify it as a Schedule V product.

Anabolic steroids were added to Schedule III of CSA as a result of the passage of the Anabolic Steroid Control Act in February 1991. FDA retained the responsibility to assure that these products are safe and effective for use as labeled, and they are not counterfeit, adulterated, or misbranded. As mentioned above, anabolic steroids which are expressly intended for administration through implants to cattle or other non-human species, and which have been approved by FDA, are not currently regulated under CSA. It is felt that this dosage form is not likely to be abused by humans.

FDA and DEA work together to determine when other drugs, including animal drugs, should become controlled substances. Normally, decisions to classify animal drugs as controlled substances are based on concerns about diversion to and abuse by humans. An example of such FDA and DEA cooperation is recent activities regarding ketamine.

Ketamine hydrochloride, an anesthetic for human and veterinary use, is a legitimately manufactured product that is being abused with increasing frequency. On the street, the drug is often called "K" or "Special K." It produces effects similar to those produced by phencyclidine (PCP), and the visual effects of LSD. With repeated daily exposure, users can develop tolerance and psychological dependence, as is the case with most controlled substances. Veterinary clinics have been burglarized for ketamine. These are among the factors that have caused the FDA and DEA to re-evaluate the control status of the drug.

FDA recently recommended that ketamine should be placed into Schedule III. DEA plans to publish a proposed rule in the Federal Register to accomplish this scheduling action.

Under Federal law, all businesses which manufacture or distribute controlled drugs, all health professionals (including veterinarians) entitled to dispense, administer or prescribe them, and all pharmacies entitled to fill prescriptions must register with the DEA. Registrants must comply with a series of regulatory requirements relating to drug security, records accountability, and adherence to standards.

Questions related to the registration process may be directed to DEA's Office of Diversion Control, Registration Unit. This unit has a toll-free number available 24 hours a day. This number, 1-800-882-9539, is equipped with a voice mail system that may be used to request:

  • New applications for registration,
  • Renewal applications,
  • Duplicate certificates of registration,
  • DEA order forms, and
  • Changes of address.

Callers may speak with a Registration Assistant during normal business hours (8:30 a.m. to 6:00 p.m. EST).