Formulation considerations for the development of medications with abuse potential

Adjunctive treatment with psychostimulants and stimulant-like drugs for resistant bipolar depression: a systematic review and meta-analysis

BACKGROUND

Depression is considered to be the most difficult to treat phase of bipolar disorder as patients experience residual symptoms causing long-term disability. This work aims to explore the role of add-on stimulant and stimulant-like medication in resistant bipolar depression patients.

METHODS

Systematic review of add-on stimulants and stimulant-like drugs in resistant bipolar depression by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Analysis was performed using the random-effects models. Heterogeneity was evaluated with Cochran's Q and I2 statistics.

RESULTS

Six randomized controlled trials of add-on modafinil, armodafinil, and lisdexamphetamine (LDX) (n = 813) vs placebo (n = 815) in the treatment of resistant bipolar depression were included. These drugs were more likely to induce remission from an episode of resistant bipolar depression (relative risk [RR] = 1.37; 95% confidence interval [CI]: 1.06-1.77; number needed to treat for an additional beneficial outcome = 16). Moreover, they did not induce more dropouts than placebo (RR = 1.04; 95% CI: 0.91-1.18), nor did they increase the risk of adverse effects (53/772 vs 41/771) at the end of treatment (RR = 1.30; 95% CI: 0.81-2.10; number needed to treat for an additional harmful outcome = 62). Suicidality and manic switch were not affected by active treatment. Heterogeneity was low (Cochran's Q: P > .05), but sometimes with a large CI.

CONCLUSIONS

LDX, modafinil, and armodafinil seem to offer a reasonably well-tolerated and safe treatment in resistant bipolar depression. Treatment guidelines should, therefore, be revised to include these medications earlier in the therapeutic algorithm for resistant acute bipolar depression. Further research is, however, necessary for the elucidation of the clinical usefulness of these and other similar compounds.

Household Diversion of Prescription Stimulants: Medication Misuse by Parents of Children with Attention-Deficit/Hyperactivity Disorder

OBJECTIVES

The primary objective of this study is to investigate household diversion of stimulant medication. Secondary objectives are to examine clinical/demographic predictors of diversion, types of formulations diverted, exposure to household diversion in the media, and storage of prescription stimulants within households.

METHODS

Questionnaires were completed by 180 parents of youth who were currently taking stimulant medication for treatment of attention-deficit/hyperactivity disorder (ADHD). Parents were asked whether they or another adult in the home had ever taken their child's stimulant medication or given one child's stimulant medication to another child in the home. Additionally, data regarding demographics, parental ADHD (diagnosed or suspected), past suspicions of missing medication, and medication storage were also collected. Responses were compared using Pearson's chi-squared test with Yates' continuity correction.

RESULTS

Sixteen percent of parents reported diversion of stimulant medication to another household member, with the majority admitting to taking the medication themselves. Another 13% had been tempted to illicitly self-administer their child's medication. Parents with suspected or diagnosed ADHD showed greater risk of self-administration or temptation to do so, compared to parents without (33% vs. 17%, p = 0.01). The majority of parents (71%) stored prescription stimulants "in plain sight," or "out of sight but available to all."

CONCLUSION

Although previous research has focused on peer diversion among adolescents and young adults, clinicians must be vigilant for the possibility of diversion by parents of children treated with stimulant medication.

Expert Opinion and Recommendations for the Management of Attention-Deficit/Hyperactivity Disorder in Correctional Facilities

There has been considerably less research on the management of adult attention-deficit/hyperactivity disorder (ADHD) among the inmates of correctional facilities than in the general community. While the successful identification and management of ADHD in the adult correctional setting offer potential benefits to the individuals themselves, to institutional staff, and to wider society, their implementation represents significant challenges. These include high prevalence rates, the low level of ADHD recognition, the high incidence of comorbid psychiatric disorders, and the high risk of abuse and diversion of prescribed medications. Here, the authors provide an overview of current recommendations for the identification and management of adults with ADHD in correctional settings and discuss possible strategies for their further development.

Pharmacological interventions for adolescents and adults with ADHD: stimulant and nonstimulant medications and misuse of prescription stimulants

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by symptoms of inattention, hyperactivity, and impulsivity that cause functional impairment. Recent research indicates that symptoms persist into adulthood in the majority of cases, with prevalence estimates of approximately 5% in the school age population and 2.5%–4% in the adult population. Although students with ADHD are at greater risk for academic underachievement and psychosocial problems, increasing numbers of students with ADHD are graduating from high school and pursuing higher education. Stimulant medications are considered the first line of pharmacotherapy for individuals with ADHD, including college students. Although preliminary evidence indicates that prescription stimulants are safe and effective for college students with ADHD when used as prescribed, very few controlled studies have been conducted concerning the efficacy of prescription stimulants with college students. In addition, misuse of prescription stimulants has become a serious problem on college campuses across the US and has been recently documented in other countries as well. The purpose of the present systematic review was to investigate the efficacy of prescription stimulants for adolescents and young adults with ADHD and the nonmedical use and misuse of prescription stimulants. Results revealed that both prostimulant and stimulant medications, including lisdexamfetamine dimesylate, methylphenidate, amphetamines, and mixed-amphetamine salts, are effective at reducing ADHD symptoms in adolescents and adults with ADHD. Findings also suggest that individuals with ADHD may have higher rates of stimulant misuse than individuals without the disorder, and characteristics such as sex, race, use of illicit drugs, and academic performance are associated with misuse of stimulant medications. Results also indicate that individuals both with and without ADHD are more likely to misuse short-acting agents than long-acting agents. These findings have implications for intervention, prevention, and future research.

An iterative model for in vitro laboratory assessment of tamper deterrent formulations

BACKGROUND

In an effort to address the continuing problem of prescription opioid abuse, manufacturers are incorporating new technologies into formulations that are designed to deter product tampering and misuse. Standards for laboratory assessment of tamper deterrent properties of new formulations have not previously been developed.

METHODS

Experimental designs were developed for the in vitro laboratory assessment of the tamper deterrent properties of reformulated oxycodone. Given that an exhaustive study of all potential tampering methods was impractical; this model was developed to evaluate the product in an incremental fashion with iterative changes that were amenable to objective and replicable laboratory testing.

RESULTS

A description of the model is provided along with pertinent examples involving assessment of reformulated oxycodone with comparisons to the original formulation. Physical and chemical procedures were developed that relate to "real-world" scenarios that may be applied to opioid formulations. Test results were interpreted in relation to the relative ease or difficulty of the manipulation as compared to control materials and the amount and purity of active drug that could be accessed. Results from some of the tests were designed to be useful in predicting whether specific tampering methods would facilitate or deter drug administration by different routes of administration.

CONCLUSIONS

This model, developed to assess the tamper deterrent properties of reformulated oxycodone, should have application in the assessment of other drug formulations designed to exhibit tamper deterrence properties.

Treating attention-deficit/hyperactivity disorder in adults: focus on once-daily medications

OBJECTIVE

To review the efficacy, safety, and abuse liability of approved treatments in adults with attention-deficit/hyperactivity disorder (ADHD), with a focus on once-daily medications.

DATA SOURCES

PubMed was searched for relevant studies/reviews in English from 2002 to 2011 on adult ADHD treatments.

STUDY SELECTION

Keywords used in the search were ADHD, adults, and treatment. Limits included only clinical trials, meta-analyses, randomized controlled trials, and reviews including adults (aged ≥ 19 years).

DATA EXTRACTION

Selection criteria returned 471 publications. Retrieved studies were excluded if they primarily focused on children, treatments not indicated for ADHD, or ADHD and comorbid conditions.

DATA SYNTHESIS

An epidemiologic survey revealed that 10.9% of adults identified with ADHD had received treatment during the prior 12 months. Treatments for ADHD in adults include pharmacologic and nonpharmacologic options. US Food and Drug Administration-approved long-acting stimulants and a nonstimulant with proven efficacy and safety profiles have been developed and include osmotic-release oral system methylphenidate hydrochloride (OROS-methylphenidate), extended-release dexmethylphenidate hydrochloride, mixed amphetamine salts extended release (MAS-XR), the nonstimulant atomoxetine hydrochloride, and the prodrug lisdexamfetamine dimesylate. Long-acting stimulants differ in formulation characteristics used to achieve extended release, with OROS-methylphenidate employing an osmotic-release technology, extended-release dexmethylphenidate hydrochloride and MAS-XR using pH-dependent beads, and lisdexamfetamine dimesylate using prodrug technology. These features variably affect pharmacokinetic characteristics, duration of action, and abuse liability. While all long-acting medications have varied pharmacokinetic features, mechanism of action, and duration of effect, all are generally efficacious and safety profiles are similar.

CONCLUSION

Approved long-acting treatments in adults with ADHD were effective in improving symptoms and were generally well tolerated.

Risk management and post-marketing surveillance of CNS drugs

Drugs affecting the central nervous system span a broad range of chemical entities, dosage forms, indications, and risks. Unintended consequences include potential abuse and overdose in non-patient drug abusers, deliberate tampering of drug dosage forms, and criminal behavior associated with diversion. Regulators must consider diverse factors to find the appropriate conditions of approval to minimize unintended consequences while enabling a level of access desired by health care providers and patients. This commentary appears as part of a special issue of Drug and Alcohol Dependence that focuses on risk management and post-marketing surveillance and addresses key issues that pose real-world challenges to pharmaceutical sponsors and regulators in particular. For example, in the U.S., Controlled Substances Act drug scheduling can be considered a risk management strategy but its legal authorities and administrative processes are independent from those of risk management (including Risk Evaluation and Mitigation Strategies or REMS); better harmonization of these approaches is vital from drug development and regulatory perspectives. Risk management would ideally be implemented on a strong science foundation demonstrating that the tools employed to mitigate risks and ensure safe use are effective. In reality, research and evaluation of tools in this area is in its infancy and will necessarily be an evolutionary process; furthermore, there is little precedent for linking interventions and program evolution to unintended consequences such as regional outbreaks of abuse and diversion. How such issues are resolved has the potential to stimulate or stifle innovations in drug development and advance or imperil health care.

Abuse liability assessment of tobacco products including potential reduced exposure products

The harm produced by tobacco products is a result of frequent use of a highly toxic product. Reducing the adverse public health impact of tobacco products might be most effectively achieved by reducing the likelihood of their use and the toxicity of the products. Products that retain some characteristics of cigarettes but have been altered with the intention of reducing toxicity have been referred to as modified risk tobacco products or potential reduced exposure products (MRTP/PREP). Evaluation of their content, emission, and toxicity is discussed in other articles in this special issue. Here, we discuss the methodology that has been used to examine the likelihood of abuse or addiction. Abuse liability assessment (ALA) methodology has been used by the Food and Drug Administration (FDA) and other drug regulatory agencies world-wide for decades to assess the risks posed by a wide variety of pharmacologically active substances. ALA is routinely required among other evaluations of safety during the pre-market assessment of new drugs, and is continually adapted to meet the challenges posed by new drug classes and drug formulations. In the 2009 law giving FDA regulation over tobacco products, FDA is now required to evaluate new tobacco products including MRTP/PREPs to determine their risk for abuse and toxicity at the population level. This article describes the traditional tools and methods of ALA that can be used to evaluate new tobacco and nicotine products including MRTP/PREPs. Such ALA data could contribute to the scientific foundation on which future public policy decisions are based.

Can abuse deterrent formulations make a difference? Expectation and speculation

It is critical that issues surrounding the abuse and misuse of prescription opioids be balanced with the need for these medications for the treatment of pain. One way to decrease the abuse of prescription opioid medications is to develop abuse deterrent formulations (or ADFs) that in some way prevent drug abusers from extracting out the active ingredient in order to employ alternate routes of administration, such as injection, snorting, and smoking. Several factors including the pharmacokinetic profile of the drug, the features of the drug formulation that make it attractive or unattractive for abuse, the type of drug abuser, the progression of one's addiction pathway, and one's social environment may all play a role in the abuse of prescription opioids and what methods are used to abuse these drugs. This paper will examine these factors in order to understand how they affect the abuse of prescription opioids and routes of administration, and how the development of ADFs may alter these patterns.

Non-medical use and abuse of commonly prescribed medications

BACKGROUND

The steep escalation in non-medical use and abuse of prescription medications in recent years has begun to seriously affect public health, calling for increased clinician awareness. Effective action and collaborative efforts are required to reduce prescription drug abuse while ensuring that availability of needed prescription medications for the majority of patients who use them appropriately is not inadvertently diminished.

OBJECTIVE

To educate physicians, clinicians, and other healthcare providers about the scope of non-medical prescription drug abuse and effective clinical management strategies to reduce abuse and diversion of prescription medications.

RESEARCH DESIGN AND METHODS

Articles were identified through PubMed and PsycINFO searches (January 2000 to November 2007). Search terms included combinations of 'prescription drug abuse', 'substance abuse', and 'non-medical use of prescription drugs'. Government agency Web sites were searched for additional references.

RESULTS

Data from recent national surveys and other published reports indicate that the lifetime prevalence of non-medical prescription drug use/abuse in the United States is approximately 20% (48 million persons aged > or = 12 years). Public health concern is further heightened by a significant increase in past-month use among adolescents (3.3% of 12-17 year olds) and young adults (6.4% of 18-25 year olds) and the vulnerability of a growing elderly population.

CONCLUSIONS

Increased clinician awareness of the scope, demographics, and current trends in prescription medication abuse can be used to enhance screening and effective clinical management skills and strategies to reduce abuse and diversion of prescription drugs without compromising access to needed medications for the majority of patients who use them appropriately.

Behavioral economic analysis of drug preference using multiple choice procedure data

The multiple choice procedure has been used to evaluate preference for psychoactive drugs, relative to money amounts (price), in human subjects. The present re-analysis shows that MCP data are compatible with behavioral economic analysis of drug choices. Demand curves were constructed from studies with intravenous fentanyl, intramuscular hydromorphone and oral methadone in opioid-dependent individuals; oral d-amphetamine, oral MDMA alone and during fluoxetine treatment, and smoked marijuana alone or following naltrexone pretreatment in recreational drug users. For each participant and dose, the MCP crossover point was converted into unit price (UP) by dividing the money value ($) by the drug dose (mg/70kg). At the crossover value, the dose ceases to function as a reinforcer, so "0" was entered for this and higher UPs to reflect lack of drug choice. At lower UPs, the dose functions as a reinforcer and "1" was entered to reflect drug choice. Data for UP vs. average percent choice were plotted in log-log space to generate demand functions. Rank of order of opioid inelasticity (slope of non-linear regression) was: fentanyl>hydromorphone (continuing heroin users)>methadone>hydromorphone (heroin abstainers). Rank order of psychostimulant inelasticity was d-amphetamine>MDMA>MDMA+fluoxetine. Smoked marijuana was more inelastic with high-dose naltrexone. These findings show this method translates individuals' drug preferences into estimates of population demand, which has the potential to yield insights into pharmacotherapy efficacy, abuse liability assessment, and individual differences in susceptibility to drug abuse.