Risperidone (Risperdal)
This is general information to help you ask better questions. It is not medical advice. Your prescriber knows your full picture. Never stop or adjust an antipsychotic without medical guidance — abrupt discontinuation can be dangerous.
Risperidone is one of the most widely prescribed antipsychotics in the world and has one of the longest track records of the second-generation medications. It is often chosen as a first-line medication, particularly for first-episode psychosis, because of its well-established efficacy, the breadth of evidence supporting its use, and the availability of a long-acting injectable form that suits some patients better than daily oral medication.
At lower doses, it tends to be reasonably well-tolerated. At higher doses, the movement-related side effects that second-generation antipsychotics were designed to reduce can become more prominent. And at any dose, it raises prolactin levels more than most alternatives, an effect that is under-discussed and worth understanding.
The long-acting injectable form - Risperdal Consta, given every two weeks - is worth knowing about even if you're currently on the oral version. For some people, removing the daily decision and the daily reminder that they're on psychiatric medication is meaningful. For others, the injection itself is a barrier. Worth discussing if the topic hasn't come up.
An honest note about limitations
Risperidone is effective for positive symptoms, like hallucinations, delusions, disorganised thinking, and has reasonable evidence for agitation and aggression. Like most antipsychotics, it does much less for negative symptoms. The prolactin elevation it causes is more pronounced than most alternatives and affects both men and women in ways that are worth knowing about before rather than after they appear.
What to expect early on
i. Sedation, particularly at the start. Usually eases over the first few weeks. Taking the dose in the evening, if your prescriber agrees, can help.
ii. Dizziness when standing up. Risperidone can lower blood pressure, particularly when changing position. Stand slowly, especially in the morning. This usually eases over time.
iii. Some weight gain. Less than olanzapine or quetiapine, more than aripiprazole or lurasidone. Worth monitoring from the start.
iv. Restlessness (akathisia). Can occur, particularly at higher doses. The inner restlessness, inability to sit still, or sensation of crawling in the legs. Worth naming to your prescriber — it is treatable and doesn't need to be endured.
v. Stiffness or slowness. More common at higher doses. If you notice muscle stiffness, slow movement, or a shuffling quality to your walk, raise it - dose adjustment or a brief course of additional medication can help.
The prolactin issue — what you need to know
Risperidone raises prolactin, a hormone produced by the pituitary gland, more than almost any other antipsychotic. This is its most distinctive and most under-discussed side effect, and it affects both men and women.
In women, elevated prolactin can cause:
Irregular or absent periods
Breast tenderness or enlargement
Unexpected milk production (galactorrhoea)
Reduced libido and difficulty with arousal
Long-term effects on bone density if prolactin remains elevated
In men, elevated prolactin can cause:
Reduced libido
Difficulty with erections or ejaculation
Breast tissue growth or tenderness (gynaecomastia)
Unexpected milk production (rare but documented)
Long-term effects on bone density
Many people are reluctant to bring these effects up with a prescriber. They're worth raising anyway - alternatives exist, and the prolactin elevation isn't a necessary feature of antipsychotic treatment; it's specific to risperidone and a few others. Your prescriber can check your prolactin level with a simple blood test if these effects are a concern.
A note on sexual side effects generally
Sexual side effects (from prolactin elevation or other mechanisms) are among the most commonly experienced but least commonly reported side effects of antipsychotic medication. Prescribers often don't ask, and patients often don't volunteer. If any aspect of your sexual function has changed since starting or adjusting this medication, it is relevant clinical information, and naming it opens the door to solutions.
Less common, but important to know
Movement effects Risperidone has a higher risk of movement-related side effects than some second-generation alternatives, particularly at doses above 6mg. Muscle stiffness, slowness, tremor, and restlessness can all occur. Tardive dyskinesia — involuntary movements of the mouth, face, or hands — is a long-term risk with any antipsychotic. Worth monitoring, particularly at higher doses or with long-term use.
Metabolic effects Moderate metabolic risk — meaningful weight gain for many people, with some impact on blood sugar and cholesterol. Less than olanzapine or quetiapine, more than aripiprazole or lurasidone. Standard metabolic monitoring applies.
DON'T WAIT THROUGH THESE: Muscle stiffness with high fever and confusion. Restlessness that is unbearable or worsening. Involuntary movements of mouth, face, or hands. Signs of significantly elevated prolactin (severe breast changes, persistent amenorrhoea). Thoughts of self-harm. Call your prescriber. In the US, call or text 988 at any time.
Things that interact
Alcohol amplifies sedation. Even moderate amounts can be noticeably stronger.
Cannabis can worsen the underlying condition and interact unpredictably.
CYP2D6 inhibitors - certain antidepressants including fluoxetine and paroxetine - can raise risperidone levels significantly. Tell every prescriber and pharmacist what you're on before anything new is added.
Carbamazepine and some other seizure medications can lower risperidone levels.
The long-acting injectable — worth knowing about
Risperdal Consta is an injection given every two weeks. Aristada (paliperidone, a closely related drug) is available monthly or even less frequently. For some people, moving from daily pills to an injectable changes their relationship with treatment, removing the daily reminder, eliminating the possibility of missed doses, and simplifying the medication routine significantly.
The transition to an injectable requires oral overlap for several weeks while the injection builds to therapeutic levels. If the current oral medication is working reasonably well and the main challenge is adherence or the daily burden, an injectable is a reasonable topic to raise.
Worth asking at your next appointment
"Can we check my prolactin level?"
"I've noticed [prolactin-related effect]. Is it related to the medication?"
"Is there an alternative with a lower prolactin effect?"
"Would the long-acting injectable be worth considering for me?"
"Are we monitoring my metabolic labs regularly?"
This is general information. Your prescriber knows your full picture - use this to ask better questions, not to make changes on your own. Never stop or adjust an antipsychotic without medical guidance.
