Lisdexamfetamine dimesylate

Neurological Effects of Stimulants and Hallucinogens

In this article, we will discuss the history, pharmacodynamics, and neurotoxicity of psychostimulants and hallucinogens. The drugs discussed are widely used and have characteristic toxidromes and potential for neurological injuries with which the practicing clinician should be familiar. Psychostimulants are a class of drugs that includes cocaine, methamphetamine/amphetamines, and cathinones, among others, which produce a crescendoing euphoric high. Seizures, ischemic and hemorrhagic strokes, rhabdomyolysis, and a variety of movement disorders are commonly encountered in this class. Hallucinogens encompass a broad class of drugs, in which the user experiences hallucinations, altered sensorium, distorted perception, and cognitive dysfunction. The experience can be unpredictable and dysphoric, creating a profound sense of anxiety and panic in some cases. Recognizing the associated neurotoxicities and understanding the appropriate management is critical in caring for these patient populations. Several of these agents are not detectable by standard clinical laboratory analysis, making identification and diagnosis an even greater challenge.

The landscape of small-molecule prodrugs

Prodrugs are derivatives with superior properties compared with the parent active pharmaceutical ingredient (API), which undergo biotransformation after administration to generate the API in situ. Although sharing this general characteristic, prodrugs encompass a wide range of different chemical structures, therapeutic indications and properties. Here we provide the first holistic analysis of the current landscape of approved prodrugs using cheminformatics and data science approaches to reveal trends in prodrug development. We highlight rationales that underlie prodrug design, their indications, mechanisms of API release, the chemistry of promoieties added to APIs to form prodrugs and the market impact of prodrugs. On the basis of this analysis, we discuss strengths and limitations of current prodrug approaches and suggest areas for future development.

Development of Child-Friendly Lisdexamfetamine Chewable Tablets Using Ion Exchange Resin as a Taste-Masking Carrier Based on the Concept of Quality by Design (QbD)

Taste masking is critical to improving the compliance of pediatric oral dosage forms. However, it is challenging for extremely bitter lisdexamfetamine dimesylate (LDX) with a long half-life and given in large dose. The present study aims to develop an immediate-release, taste-masked lisdexamfetamine chewable tablet. Lisdexamfetamine-resin complexes (LRCs) were prepared using the batch method. The molecular mechanism of taste masking was explored by PXRD, PLM, STA, and FT-IR. The results showed that taste masking was attributed to the ionic interaction between drug and the resin. The ion exchange process conformed to first-order kinetics. The rate-limiting step of drug release was the diffusion of ions inside the particles, and the concentration of H⁺ was the key factor for immediate release. The masking efficiency of the prepared LRCs in saliva exceeded 96%, and the drug could be completely released within 15 min in aqueous HCl (pH 1.2). Furthermore, the SeDeM expert system was used for the first time to comprehensively study the powder properties of LRCs and to quickly visualize their defects (compressibility, lubricity/stability, and lubricity/dosage). The selection of excipients was targeted rather than traditional screening, thus obtaining a robust chewable tablet formulation suitable for direct compression. Finally, the difference between chewable tablets containing LRCs and chewable tablets containing lisdexamfetamine dimesylate was compared by in vitro dissolution test, electronic tongue, and disintegration test. In conclusion, an immediate-released, child-friendly lisdexamfetamine chewable tablets without bitterness was successfully developed by the QbD approach, using the SeDeM system, which may help in further development of chewable tablets.

Quercetin-Amino Acid Conjugates are Promising Anti-Cancer Agents in Drug Discovery Projects

Quercetin is a plant flavonoid with great potential for the prevention and treatment of disease. Despite the curative application of quercetin is hampered by low bioavailability, its core serves as a scaffold for generating more potent compounds with amplified therapeutic window. This review aims to describe recent advances in the improvement of the pharmacokinetic profile of quercetin via the amino acid prodrug approach which offers wide structural diversity, physicochemical and biological properties improvement. According to the findings, conjugation of quercetin with amino acids results in increased solubility, stability, cellular permeability as well as biological activity. In particular quercetin- amino acid conjugates exhibited potent anticancer, MDR-reversal and antibiotic resistance reversal activities. The synthetic pathways and examples of quercetin-amino acid conjugates are considered. Practical considerations and challenges associated with the development of these prodrugs are also discussed. This mini-review covers the literature on quercetin-amino acid conjugates since 2001 when the first thematic work was published.

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.

PEPT1-mediated prodrug strategy for oral delivery of peramivir

Peramivir was a novel and highly potent neuraminidase (NA) inhibitor for the treatment of influenza A and B. However, it exhibited a very low oral bioavailability (only 3%) due to the high polarity (log P of -1.4) and the low membrane permeability across the intestine. To utilize the PEPT1-mediated prodrug strategy to improve the oral absorption and develop the oral alternative, seven amino acid ester prodrugs and seven amino acid amide prodrugs have been synthesized. The permeability of these prodrugs across Caco-2 cells were screened. Peramivr-(CH2)2-l-Val and Peramivir-l-Ile were of the highest permeability in ester prodrugs and amide prodrugs, respectively, and then they were selected for further studies. Glycylsarcosine (gly-sar) uptake by Caco-2 could be inbihited by Peramivir-(CH2)2-l-Val and Peramivir-l-Ile in a concentration-dependent manner, and the IC50 was 1.34 ± 0.31 mM and 1.78 ± 0.48 mM, respectively. The direct uptake of Peramivir-(CH2)2-l-Val and Peramivir-l-Ile in MDCK-PEPT1 cells were significantly higher than in MDCK mock cells, and could be markedly inhibited by gly-sar. The uptake of Peramivir-(CH2)2-l-Val and Peramivir-l-Ile (0.01 to 50 mM) in MDCK-hPEPT1 cells conformed to Michaelis-Menten Equation. The oral bioavailability of peramivir was 65.3% and 37.3% after the oral administration of Peramivir-(CH2)2-l-Val and Peramivir-l-Ile to rats, respectively. The oral absorption and bioactivation of Peramivir-(CH2)2-l-Val was rapid and extensive, and no Peramivir-(CH2)2-l-Val was found in plasma. Because the amide bond was relatively stable, Peramivir-l-Ile could not be totally converted to the parent drug in vivo. Peramivir-(CH2)2-l-Val with good oral profiles and rapid bioactivation might be a promising prodrug for the further clinic development. The present study also corroborated the idea that the PEPT1-mediated prodrug approach has enormous promise for improving the oral absorption of poorly absorbed drug.

Lisdexamfetamine: A Review in ADHD in Adults

Lisdexamfetamine dimesylate (lisdexamfetamine) is a long-acting amfetamine prodrug with a convenient once-daily oral regimen that offers the potential for improved adherence and reduced abuse compared with short-acting preparations of amfetamines. Lisdexamfetamine (as Elvanse Adult(®); Tyvense Adult™) has been approved for use in adults with attention-deficit hyperactivity disorder (ADHD) under the EU decentralization procedure, with the first approvals in the UK, Sweden and Denmark. This approval reflects the results of three short-term trials in adults with ADHD in which fixed- or flexible-dose lisdexamfetamine produced significantly greater improvements than placebo in ADHD symptoms, overall functioning, executive functioning (including in patients with significant pre-existing impairment) and quality of life. Of note, a post hoc analysis of one of these studies suggested that the response to lisdexamfetamine was generally similar in treatment-naïve patients and those who had already received-and not responded satisfactorily to-previous ADHD therapies, including methylphenidate (MPH). Two further studies demonstrated the longer-term effectiveness of flexible-dose lisdexamfetamine in reducing ADHD symptoms, albeit maintenance of efficacy required ongoing treatment with the drug. Lisdexamfetamine was generally well tolerated in clinical trials, with an adverse event profile typical of that reported for other long-acting stimulants. Head-to-head comparisons with other long-acting agents, notably MPH and atomoxetine, are lacking. Nonetheless, on the basis of the available data, lisdexamfetamine provides a useful alternative option for the treatment of adults with ADHD, including those who have not responded adequately to previous ADHD therapies, including MPH.

Amino acids as promoieties in prodrug design and development

Prodrugs are biologically inactive agents that upon biotransformation in vivo result in active drug molecules. Since prodrugs might alter the tissue distribution, efficacy and the toxicity of the parent drug, prodrug design should be considered at the early stages of preclinical development. In this regard, natural and synthetic amino acids offer wide structural diversity and physicochemical properties. This review covers the use of amino acid prodrugs to improve poor solubility, poor permeability, sustained release, intravenous delivery, drug targeting, and metabolic stability of the parent drug. In addition, practical considerations and challenges associated with the development of amino acid prodrugs are also covered.

New and extended-action treatments in the management of ADHD: a critical appraisal of lisdexamfetamine in adults and children

Treatment guidelines from the American Academy of Child and Adolescent Psychiatry and the American Academy of Pediatrics state that stimulant medications have the most evidence for safety and efficacy in the treatment of childhood attention deficit hyperactivity disorder (ADHD). Longer-acting stimulants are thus considered as first-line for management of ADHD symptoms. Over the years, concerns about the abuse potential of stimulants have led to the development of alternative formulations of these agents. One such recent development, lisdexamfetamine (LDX) was FDA approved for treating ADHD in children in early 2007 and in adults in early 2008. LDX is a prodrug, which when orally ingested, is converted to l- lysine and active d-amphetamine, which is responsible for its therapeutic activity. This unique formulation may lead to a possible reduction of the abuse potential, by bypassing the first-pass metabolism. In fact, a statistically significant difference for the 'liking' effects on the Drug Questionnaire Response has been reported with intravenous LDX compared to d-amphetamine. LDX appears to have an efficacy and tolerability profile comparable to other extended-release stimulant formulations used to treat ADHD, but reduced potential for abuse-related liking effects when compared to equivalent amounts of immediate-release d-amphetamine. The most common adverse events include decreased appetite, insomnia, upper abdominal pain, headache, irritability, weight loss, and nausea.

Natural products to drugs: natural product-derived compounds in clinical trials

Natural product and natural product-derived compounds that are being evaluated in clinical trials or are in registration (as at 31st December 2007) have been reviewed, as well as natural product-derived compounds for which clinical trials have been halted or discontinued since 2005. Also discussed are natural product-derived drugs launched since 2005, new natural product templates and late-stage development candidates.