Adult Treatment

Drug treatment is the first-line treatment for adults with ADHD with either moderate or severe levels of impairment. Methylphenidate is the first-line drug.

There is the potential for drug misuse and diversion in adults with ADHD, especially in some settings, such as prison, although there is no strong evidence that this is a significant problem.

For adults with ADHD, drug treatment should be the first-line treatment unless the person would prefer a psychological approach. (At the time of publication dexamfetamine and lisdexamfetamine did not have SFDA Approval. Informed consent should be obtained and documented.)

Table 1

Name

Methylphenidate

Indication

First-line drug

Authorization Status (SFDA)

Authorized

Dosage

  • Initial treatment should begin with low doses (5 mg three times daily for immediate-release preparations; the equivalent dose for modified-release preparations)
  • The dose should be titrated against symptoms and side effects over 4 to 6 weeks
  • The dose should be increased according to response up to a maximum of 100 mg/day
  • Modified-release preparations should usually be given once daily and no more than twice daily
  • Modified-release preparations may be preferred to increase adherence and in circumstances where there are concerns about substance misuse or diversion
  • Immediate-release preparations should be given up to four times daily

Special Precautions & Monitoring

  • Weight should be measured 3 and 6 months after drug treatment has started and every 6 months thereafter
  • For people who have sustained resting tachycardia, arrhythmia or systolic blood pressure greater than the 95th percentile (or a clinically significant increase) measured on two occasions should have their dose reduced and be referred to adult physician.
  • If psychotic symptoms (for example, delusions and hallucinations) emerge starting methylphenidate the drug should be withdrawn and a full psychiatric assessment carried out. Atomoxetine could be considered as an alternative.
  • If tics emerge in people taking methylphenidate, healthcare professionals should consider whether:
    • The tics are stimulant-related (tics naturally wax & wane)
    • Tic-related impairment outweighs the benefits of ADHD treatment
  • If tics are stimulant-related, reduce the dose of methylphenidate; consider changing to atomoxetine, or stop drug treatment.
  • Anxiety symptoms, including panic, may be precipitated by stimulants, particularly in adults with a history of coexisting anxiety. Where this is an issue, lower doses of the stimulant and/or combined treatment with an antidepressant used to treat anxiety can be used; switching to atomoxetine may be effective

Table 2

Name

Atomoxetine

Indication

  • In adults unresponsive or intolerant to an adequate trial of methylphenidate (this should usually be about 6 weeks).
  • Where there may be concern about the potential for drug misuse and diversion (for example, in prison services), atomoxetine may be considered as the first-line drug treatment for ADHD in adults.

Authorization Status (SFDA)

Authorized

Dosage

  • For people with ADHD weighing up to 70 kg, the initial total daily dose should be approximately 0.5 mg/kg; the dose should be increased after 7 days to approximately 1.2 mg/kg/day
  • For people with ADHD weighing more than 70 kg, the initial total daily dose should be 40 mg; the dose should be increased after 7 days up to a maintenance dose of 100 mg/day
  • The usual maintenance dose is either 80 or 100 mg, which may be taken in divided doses
  • A trial of 6 weeks on a maintenance dose should be allowed to evaluate the full effectiveness of atomoxetine

Special Precautions & Monitoring

  • People treated with atomoxetine should be observed for agitation, irritability, suicidal thinking and self-harming behaviour, and unusual changes in behaviour, particularly during the initial months of treatment, or after a change in dose.
  • For people who have sustained resting tachycardia, arrhythmia or systolic blood pressure greater than the 95th percentile (or a clinically significant increase) measured on two occasions should have their dose reduced and be referred to adult physician.
  • Sexual dysfunction (that is, erectile and ejaculatory dysfunction) and dysmenorrhoea should be monitored as potential side effects of atomoxetine

Table 3

Name

Dexamfetamine or
Lisdexamfetamine

Indication

In adults unresponsive or intolerant to an adequate trial of methylphenidate (this should usually be about 6 weeks).

Authorization Status (SFDA)

At time of publication, not approved by SFDA

Dosage

  • Initial treatment should begin with low doses (5 mg twice daily)
  • The dose should be titrated against symptoms and side effects over 4 to 6 weeks
  • Treatment should be given in divided doses
  • The dose should be increased according to response up to a maximum of 60 mg/day
  • The dose should usually be given between two and four times daily

Special Precautions & Monitoring

  • If psychotic symptoms (for example, delusions and hallucinations) emerge starting methylphenidate or dexamfetamine, the drug should be withdrawn and a full psychiatric assessment carried out. Atomoxetine could be considered as an alternative.
  • For people who have sustained resting tachycardia, arrhythmia or systolic blood pressure greater than the 95th percentile (or a clinically significant increase) measured on two occasions should have their dose reduced and be referred to adult physician.
  • If tics emerge in people taking dexamfetamine, healthcare professionals should consider whether:
    • The tics are stimulant-related (tics naturally wax and wane)
    • Tic-related impairment outweighs the benefits of ADHD treatment
  • If tics are stimulant-related, reduce the dose of dexamfetamine; consider changing to atomoxetine, or stop drug treatment.
  • Anxiety symptoms, including panic, may be precipitated by stimulants, particularly in adults with a history of coexisting anxiety. Where this is an issue, lower doses of the stimulant and/or combined treatment with an antidepressant used to treat anxiety can be used; switching to atomoxetine may be effective