amphetamine/dextroamphetamine

Action and Spectrum

Actions and Spectrum:  

Action: 

amphetamine and dextroamphetamine act on the neurotransmitters dopamine, norepinephrine, and serotonin in the brain. This drug induces the release of these neurotransmitters into the synapse, which results in their increased availability to bind to receptors.This results in an increase in overall brain activity, leading to increased focus, attention, and alertness. 

Spectrum:  

amphetamine and dextroamphetamine are primarily used in the treatment of ADHD and narcolepsy. In ADHD, they help to reduce symptoms such as inattention, hyperactivity, and impulsivity. In narcolepsy, they help to reduce excessive daytime sleepiness and improve alertness. 

Drug Interaction

Adverse Reaction

Frequency defined  

>10% (Extended Release) 

Abdominal pain (11-14%) 

Insomnia (12-27%) 

Loss of appetite (22-36%) 

Weight loss (4-11%) 

Abdominal pain (11-14%) 

Headache (<26%)  

1-10% (Extended Release) 

Anxiety (8%) 

Tachycardia (6%) 

Nausea (5-8%) 

Emotional lability (2-9%) 

Infection (4%) 

Diarrhea (2-6%) 

Fever (5%) 

Vomiting (7%) 

Dizziness (2-7%) 

Nervousness (6%) 

Black Box Warning

Black Box Warning:  

The black box warning for amphetamine/dextroamphetamine (Adderall) is related to the risk of abuse and dependence.  

The stimulant medication is commonly used to treat attention deficit hyperactivity disorder (ADHD) and narcolepsy. The black box warning highlights the potential for abuse, which can lead to dependence, addiction, and serious cardiovascular events. 

The black box warning specifically states that amphetamine/dextroamphetamine should be prescribed cautiously and for short-term use only in patients with a history of substance abuse or dependence.

Contraindication / Caution

Contraindication/Caution:  

Hypersensitivity: Individuals with a known hypersensitivity or allergy to amphetamine or dextroamphetamine, or any other ingredients in the medication should not take it.  

Cardiovascular disease: Patients who have advanced arteriosclerosis, symptomatic cardiovascular disease, moderate to severe hypertension, or other significant cardiac issues are not recommended to use this drug  

Glaucoma: The drug should not be used in patients with known or suspected glaucoma or a history of closed-angle glaucoma.  

Hyperthyroidism: This medication is contraindicated in patients with hyperthyroidism, as it may exacerbate the condition.  

Substance abuse: Individuals who have a history of alcohol or drug abuse may be more susceptible to abuse or addiction to this medication and should refrain from using it. 

Agitation: This drug may exacerbate symptoms of agitation, anxiety, or psychosis, and should be avoided in patients with these conditions.  

MAO inhibitors: This drug is contraindicated in patients taking monoamine oxidase inhibitors (MAOIs) or who have taken them within the last 14 days, as this can lead to dangerous interactions and potentially life-threatening side effects. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: N/A 

Lactation: Excreted into human milk is unknown 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

Category B: There were a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.   

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.   

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category

Pharmacology

Pharmacology:

The drug combines two stimulant drugs that act on the central nervous system. The drug is primarily used to treat attention deficit hyperactivity disorder (ADHD) and narcolepsy. 

Pharmacodynamics: 

The drug’s pharmacodynamics is related to its impact on the central nervous system, where it acts as a powerful stimulant.  

MOA:  The mechanism of action of this drug is thought to involve inhibition of the reuptake of dopamine, norepinephrine, and serotonin, thereby increasing their levels in the brain and promoting their release from the synaptic clefts.  

Pharmacokinetics: 

Absorption 

The drug is readily absorbed from the gastrointestinal tract and reaches its maximum plasma concentration about three hours after oral administration. 

Distribution 

The drug exhibits extensive distribution throughout the body and has the ability to penetrate the blood-brain barrier. It is highly lipophilic and can accumulate in adipose tissue, leading to a long half-life. 

Metabolism 

Metabolism of the drug occurs primarily in the liver through deamination and oxidation process. The major metabolites are 4-hydroxyamphetamine and norephedrine.  

Elimination and excretion The drug and its metabolites are excreted primarily in the urine, with about 30-40% of the drug excreted unchanged.

Adminstartion

Administration:   

Dosage: The appropriate dosage for this medication may differ based on factors such as the patient’s age, weight, and medical condition. It is crucial to adhere to the prescribed dosage guidelines given by a healthcare practitioner.  

Timing: The drug is usually taken once or twice a day, depending on the patient’s needs. It is typically taken in the morning or early afternoon to avoid interfering with sleep. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: amphetamine/dextroamphetamine 

Why do we use amphetamine/dextroamphetamine?  

These medications increase neurotransmitters in the brain, such as dopamine and norepinephrine. This can improve attention, concentration, and alertness, and help individuals with ADHD to better control their impulses and manage their symptoms.

Additionally, the drug can help individuals with narcolepsy stay awake during the day and improve their overall functioning. It is crucial to note that these drugs may cause adverse effects and should be taken under the guidance of a healthcare professional.