Side and Adverse Effects
In general, the side effects of stimulants are mild and often disappear in a few days after a person’s body has gotten used to the medication. However there are some mild side effects that are common and some serious adverse effects that are rare. The benefits of stimulants should be balanced against the possibility and severity of potential side effects. Fortunately, if a person has had a good medical and psychological screening, the most severe adverse effects like paranoia, psychosis, or serious heart problems are very uncommon and sudden death caused by stimulants is very, very rare in people without a heart condition or a family history of heart problems early in life (<30 years of age.)
Side/Adverse Effects
Here are the side effects and serious adverse effects in the approximate order of frequency that I’ve seen in my practice:
Most common:
- Dry mouth. This is not cause by the body getting dehydrated so drinking lots of water does not help. It is caused by the stimulants reducing the amount of saliva that is secreted by the salivary glands so drinking frequent small sips of water does help. There are some over the counter aids, like Slippery Elm, that some people can tolerate and find helpful.
- Loss of appetite and weight loss. Some people like the weight loss, others don’t. It can be minimized by taking the medication during of after meals. The weight loss tends to last a few months if the medication is taken regularly but often returns to the previous weight over time.
- Difficulty falling asleep or insomnia. It is best to avoid taking stimulants too close to bed time. For short acting stimulants, this usually means four or five hours beforehand, but for some people, the length of time required may be six hours. In unusual cases, people cannot sleep well at night if they have taken their stimulant in the morning.
- Jitteriness. This has been helped by atenolol (usually used for blood pressure reduction or extra heart beats) or benzodiazepines (Xanax and others).
Somewhat common:
- Headache (usually when a person has recently started taking stimulants)
- Upset stomach, diarrhea. This usually occurs for only a day or so when a person has recently started taking stimulants but rarely it continues and has make it impossible for some people to take stimulants.
- Depression, most commonly when the effects of the last dose of stimulants, particularly methylphenidate based medications, is wearing off late in the day. But sometimes these medications can cause make people very grumpy and irritable even early in the day. A few patients of mine have increased their dose as planned, despite this, and these side effects have disappeared. But it would be best to check with your doctor about this.
- Slightly increased blood pressure, some increase in heart beat. This is different and of less concern than episodes of fast or irregular heart beat, which should be promptly brought to your doctor’s attention.
- Difficulty urinating, sometimes constipation, may be worse during periods of stress
- Various symptoms (headache, stomach ache, dizziness, and others) that are cause not by the stimulants but by stopping another medication, like Paxil or Effexor, at the same time the stimulants are started. What may appear to be side effects are sometimes withdrawal effects from stopping the other medication.
- Increased blood pressure or pulse. In a study of the effects of methylphenidate (MPH) on ECG, systolic and diastolic blood pressure, and heart rate, 114 adolescent with ADHD were given up to 0.68 mg per pound per day of Concerta (long acting MPH) for a six month period. This would be equivalent to about 34 mg of MPH twice a day for a 100 pound person or 47 mg twice a day for a 150 pound person. A small but not clinically significant increase in diastolic BP and in heart rate was observed at 6 weeks without further increases during a 6 months’ follow-up. No serious cardiovascular adverse events occurred. These observations are consistent with previous reports on people using lower doses. Hammerness, P et al: J Pediatr. 2009 Jul;155(1):84-9, 89.e1. Epub 2009 Apr 25 2009
Uncommon
- Cold hands and feet, blue fingers or toes (may increase symptoms of Reynaud’s syndrome)
- Irregular heart beat
- Heartburn from amphetamines. Some people have found it helpful to grind up the pill and take it with some milk. Consult your doctor about other possible causes of the heartburn to be sure it is being caused by the amphetamines.
- Loss of sense of humor, increased seriousness, hyperfocus. This can usually be dealt with by slightly reducing the dose of the stimulant.
- Tics or twitches. Stimulants can make these better, worse, or not affect them at all.
- Sexual side effects. These include decreased or increased sexual feeling or functioning. For men, this may be helped by medications like Viagra or Cialis. Some men also experience a slightly decrease in penis size.
Rare
- Increase in intra-ocular pressure that can make glaucoma worse
- Suspiciousness and paranoia
- Psychosis
- Mania
Very rare
