Lisdexamfetamine

Lisdexamfetamine

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Systematic (IUPAC) name
N-[(2S)-1-phenylpropan-2-yl]-L-lysinamide
Clinical data
Pregnancy category	C
Routes of administration	Oral
Legal status
Legal status	US: Schedule II
Pharmacokinetic data
Bioavailability	28%
Metabolism	Gastro-intestinal (initial); Hepatic (extensively CYP2D6) after conversion to d-amphetamine
Biological half-life	< 1 hour (prodrug molecule), 12-13 hours (d-amphetamine)
Excretion	Renal: ~2%
Identifiers
CAS Number	608137-32-2
ATC code	none
PubChem	CID 11597697
DrugBank	DB01255
ChemSpider	9772457
Synonyms	(S)-2,6-diamino-N-[(S)-1-phenylpropan-2-yl]hexanamide
Chemical data
Formula	C15H25N3O
Molar mass	263.378 g/mol[[]]
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Lisdexamphetamine (L-lysine-D-amphetamine; sold as Vyvanse) is a psychostimulant prodrug of the phenethylamine and amphetamine chemical classes. Its molecular structure consists of dextroamphetamine coupled with the essential amino acid L-lysine.

Lisdexamfetamine itself is inactive and acts as a prodrug to dextroamphetamine upon cleavage of the lysine portion of the molecule. It was developed for the intention of creating a longer-lasting and more difficult to abuse version of dextroamphetamine, as the requirement of conversion into dextroamphetamine in the gastrointestinal tract increases its duration and renders it ineffective upon any other ingestion routes than the oral route. Intravenously administered lisdexamfetamine initially produced effects similar to placebo, and therefore intravenous abuse is completely ineffective; there is no increased onset or effect as occurs with IV administration of dextroamphetamine compared to oral use of the same.

Lisdexamfetamine is indicated for the treatment of attention deficit hyperactivity disorder (ADHD) in children 6-12 years and in adults (April2008) as an integral part of a total treatment program that may include other measures (i.e. psychological, educational, social). The safety and efficacy of lisdexamfetamine dimesylate in patients 3- to 5-years-old have not been established.

As opposed to Adderall, which contains roughly 75% dextroamphetamine and 25% levoamphetamine, lisdexamfetamine is a single-enantiomer (dextro) amphetamine formula. This pure formulation may reduce side effects, but certain individuals exhibit a better clinical response to the mixed isomer preparation.

Dosage

File:Lisdexamfetamine caps.jpg

70mg Vyvanse capsules

Lisdexamfetamine is available under the brand-name Vyvanse. Vyvanse comes in several different dosages (see table below). All of these dosages come in the form of 30 capsules, each of which contains the labeled dose to be taken once daily.

Vyvanse dosage strengths available
Strength	Appearance	Imprint (unique label)
20 milligrams	Capsule with ivory colored body and cap	NRP104 20 mg
30 milligrams	Capsule with white colored body and orange colored cap	NRP104 30 mg
40 milligrams	Capsule with white colored body and teal colored cap	NRP104 40 mg
50 milligrams	Capsule with white colored body and blue colored cap	NRP104 50 mg
60 milligrams	Capsule with aqua blue colored body and cap	NRP104 60 mg
70 milligrams	Capsule with blue colored body and orange colored cap	NRP104 70 mg

A 25 mg Vyvanse capsule would be molecularly equivalent to a 10 mg Dexedrine Spansule (both are about 7.425mg dextroamphetamine base), although a 25 mg Vyvanse capsule is not commercially available. However, the molecular equivalence ratio does not mean that the respective doses of Vyvanse and Dexedrine XR (Spansule) are bioequivalent because the two formulations have slightly different pharmacokinetic profiles. For example, while the area under the curve for the aforementioned pharmaceuticals is equivalent, the peak exposure (C_max) to the active compound dextroamphetamine is about 50% higher for Vyvanse than for Dexedrine XR.

History

Vyvanse was developed by New River Pharmaceuticals, who were bought by Shire Pharmaceuticals shortly before lisdexamfetamine began being marketed. Vyvanse is approved by the U.S. Food and Drug Administration (FDA) for the treatment of attention-deficit hyperactivity disorder. Vyvanse pills are available in dosages of up to 70 mg (for 12 hours).

On April 23, 2008, Vyvanse received FDA approval for the adult population . In a randomized, double-blind, four-week phase III trial in adult patients with ADHD, 30, 50 or 70mg/day of oral lisdexamfetamine caused a significantly greater improvement in ADHD-Rating Scale total score than placebo.

On February 19, 2009, Health Canada approved 30 mg and 50 mg capsules of lisdexamfetamine for treatment of ADHD.

Misuse potential

Lisdexamfetamine has potential for causing severe addiction, especially if used for long periods of time. Misuse of lisdexamfetamine may cause serious and potentially fatal cardiovascular abnormalities or even sudden death.

Warnings and Precautions

Serious Cardiovascular Events

Sudden Death and Pre-existing Structural Cardiac Abnormalities or Other Serious Heart Problems

Children and Adolescents Sudden Death and Pre-existing Structural Cardiac Abnormalities or Other Serious Heart Problems has been reported in association with CNS stimulant treatment at usual doses in children and adolescents with structural cardiac abnormalities or other serious heart problems. Although some serious heart problems alone carry an increased risk of sudden death, stimulant products generally should not be used in children or adolescents with known serious structural cardiac abnormalities, cardiomyopathy, serious heart rhythm abnormalities, or other serious cardiac problems that may place them at increased vulnerability to the sympathomimetic effects of a stimulant drug.

Adults Sudden death, stroke, and myocardial infarction have been reported in adults taking stimulant drugs at usual doses for ADHD. Although the role of stimulants in these adult cases is unknown, adults have a greater likelihood than children of having serious structural cardiac abnormalities, cardiomyopathy, serious heart rhythm abnormalities, coronary artery disease, or other serious cardiac problems. Adults with such abnormalities should also generally not be treated with stimulant drugs.

Hypertension and Other Cardiovascular Conditions

Stimulant medications cause a modest increase in average blood pressure (about 2- 4 mm Hg) and average heart rate (about 3-6 bpm) and individuals may have larger increases. While the mean changes alone would not be expected to have short-term consequences, all patients should be monitored for larger changes in heart rate and blood pressure. Caution is indicated in treating patients whose underlying medical conditions might be compromised by increases in blood pressure or heart rate, e.g. those with pre-existing hypertension, heart failure, recent myocardial infarction, or ventricular arrhythmia.

Psychiatric Adverse Events

Pre-existing Psychosis

Administration of stimulants may exacerbate symptoms of behavior disturbance and thought disorder in patients with a pre-existing psychotic disorder.

Bipolar Illness

Particular care should be taken in using stimulants to treat ADHD in patients with comorbid bipolar disorder because of concern for possible induction of a mixed/manic episode in such patients. Prior to initiating treatment with a stimulant, patients with comorbid depressive symptoms should be adequately screened to determine if they are at risk for bipolar disorder. Such screening should include a detailed psychiatric history, including a family history of suicide, bipolar disorder, and depression. Emergence of New Psychotic or Manic Symptoms Treatment-emergent psychotic or manic symptoms, e.g. hallucinations, delusional thinking, or mania in children and adolescents without a prior history of psychotic illness or mania, can be caused by stimulants at usual doses. If such symptoms occur, consideration should be given to a possible causal role of the stimulant, and discontinuation of treatment may be appropriate. In a pooled analysis of multiple short-term, placebo-controlled studies, such symptoms occurred in about 0.1% (4 patients with events out of 3482 exposed to methylphenidate or amphetamine for several weeks at usual doses) of stimulant-treated patients compared to 0 in placebo-treated patients.

Aggression

Aggressive behavior or hostility is often observed in children and adolescents with ADHD, and has been reported in clinical trials and the postmarketing experience of some medications indicated for the treatment of ADHD. Although there is no systematic evidence that stimulants cause aggressive behavior or hostility, patients beginning treatment of ADHD should be monitored for the appearance of, or worsening of, aggressive behavior or hostility.

Adverse side effects

See also: Dextroamphetamine effects

The side effects of lisdexamfetamine are similar to other amphetamine preparations. Many individuals taking lisdexamfetamine will experience side effects, but for the majority the severity of the side effects is not severe. Lisdexamfetamine, like other amphetamines, can cause severe and possibly life-threatening side effects and even sudden death in sensitive individuals.

In a clinical study for Vyvanse, 10% of patients taking lisdexamfetamine withdrew from the study due to adverse reactions compared to 1% taking placebo.

Common side effects

Common side effects (side effects that have average rates of presentation; usually presenting in >5% of patients) of lisdexamfetamine use include:

• Dizziness
• Mild agitation (restlessness)
• Nausea
• Xerostomia (dry mouth)
• Bruxism (jaw clenching/grinding)

• Anxiety
• Diarrhea
• Emesis (vomiting)
• Headache
• Insomnia - an inability to sleep.
• Weight loss(decreased appetite)

• Diaphoresis (increased sweating)
• Irritability
• Parageusia (unpleasant taste)
• Upper abdominal pain
• Cold Feet

Severe side effects

Very infrequent but possibly severe side effects requiring immediate medical attention may be caused by lisdexamfetamine; these serious reactions include:

• Severe aggression some patients have reported sudden mood changes, inability to control rage, physical abuse of others
• Abnormal muscle weakness or tiredness
• Anaphylaxis - a severe allergic reaction with effects including a rash, hives, itching, difficulty breathing, and generalized swelling.
• Changes in vision
• Dyspnea (shortness of breath)
• Fever
• Severe headache
• Syncope (fainting)

• Angina pectoris (severe chest pain)
• Blurred vision
• Cardiac dysrhythmias - a group of cardiovascular conditions in which the electrical activity of the heart is abnormal with effects ranging from a fast heartbeat to cardiac arrest and sudden death.
• Seizures
• Tics - sudden, stereotyped, nonrhythmic and repetitive motor movements and/or vocalizations.
• Euphoria

• Hallucinations
• Muscle tremors
• Severe irritability
• Severe psychomotor agitation
• Altered sexual ability or desire such as hypersexuality, male impotence, premature ejaculation, etc.
• Tachycardia (fast heartbeat)
• Slowed thinking
• Unstable emotions

See also

• ADHD
• Adderall
• Amphetamine
• Anorectics
• Desoxyn
• Dextroamphetamine
• Dopaminergics
• Methamphetamine
• Midodrine
• Phenethylamines
• Pro-drug
• Recreational Drugs
• Stimulants

References

es:Lisdexanfetamina