Rasagiline: Mechanism of Action, Indications and Important Notes
Rasagiline is an active substance from the group of monoamine oxidase B inhibitors (MAO-B inhibitors) used to treat Parkinson's disease. The active substance has been available since the early 2000s and is approved both as monotherapy in early phases of the disease and as an add-on to levodopa in more advanced stages. Rasagiline is one of the best-investigated active substances in modern Parkinson's therapy.
Parkinson's disease arises from the progressive loss of dopaminergic nerve cells in the substantia nigra of the brain. Dopamine is an important neurotransmitter for the control of movement. Rasagiline targets a central metabolic pathway for dopamine, thereby increasing the available quantity of dopamine in the brain.
Mechanism of Action
Rasagiline selectively and irreversibly inhibits the enzyme monoamine oxidase B (MAO-B). MAO-B is one of the most important enzymes that metabolises dopamine in the brain. By inhibiting this enzyme, dopamine breakdown is slowed, so that more dopamine is available at synaptic connections. This leads to an improvement in dopaminergic signal transmission in the motor circuits of the brain.
Because rasagiline inhibits MAO-B irreversibly, the effect continues even after the active substance is discontinued, until new MAO-B molecules are synthesised by the body. This explains why rasagiline is taken once daily and achieves a consistent effect over 24 hours. Compared to reversible MAO-B inhibitors, the onset of action is more stable and dose titration is simpler.
Rasagiline differs chemically and pharmacologically from older MAO inhibitors such as selegiline and shows higher selectivity for MAO-B over MAO-A. This is clinically significant, since inhibition of MAO-A can lead to so-called tyramine food interactions (cheese effect), which does not occur with selective MAO-B inhibitors at therapeutic doses.
Indications
Monotherapy in Early Parkinson's Disease
In early stages of Parkinson's disease, rasagiline can be used as monotherapy when symptoms are still moderate and levodopa therapy is not yet required. At this stage, rasagiline can favourably influence motor symptoms such as tremor, rigidity and bradykinesia. It offers the advantage of being able to delay levodopa therapy, which can be beneficial with regard to later levodopa-associated complications.
Combination Therapy with Levodopa
In more advanced stages of Parkinson's disease, rasagiline is frequently used as an add-on to levodopa. In this combination, rasagiline can reduce so-called wearing-off phenomena. Wearing-off refers to the waning of levodopa effect towards the end of a dosing interval, before the next dose is taken. The prolonged dopamine availability due to MAO-B inhibition can shorten these phases and improve motor control.
Non-Motor Symptoms
More recent investigations suggest that rasagiline may also have positive effects on non-motor symptoms of Parkinson's disease, including sleep disturbances and certain cognitive impairments. These aspects are the subject of ongoing research and play an increasing role in individualised treatment planning.
Dosage Form and Dosing
Rasagiline is available as tablets for oral administration. The usual dose is 1 mg once daily, independent of meals. Administration can take place at any time of day, but should be at the same time each day to ensure a consistent drug concentration. A dose adjustment may be necessary in patients with mild hepatic impairment. In moderate or severe hepatic impairment, rasagiline is contraindicated.
Important Notes
Several important points must be noted when combining rasagiline with other active substances. Certain antidepressants, particularly those that inhibit serotonin reuptake (SSRIs, SNRIs) or contain serotonin precursors such as tryptophan, can trigger a so-called serotonin syndrome in combination with MAO inhibitors. This can manifest through restlessness, muscle twitching, sweating, and in severe cases life-threatening symptoms. Medical consultation before the simultaneous use of such agents is absolutely necessary.
Certain pain medications such as tramadol, meperidine and some other opioids can also be problematic in combination with MAO inhibitors. The treating physician should always be informed about all medications being taken, including over-the-counter preparations.
Regular neurological follow-up is important in Parkinson's disease to assess therapeutic success and adjust therapy as needed. Since the disease is progressive, therapeutic requirements change over time.
Adverse Effects
Rasagiline is well tolerated by most patients. Possible adverse effects include:
- Headache, especially at the beginning of therapy
- Flu-like symptoms such as fatigue and general malaise
- Joint and muscle pain
- Dizziness and lightheadedness, particularly on standing up (orthostatic hypotension)
- Nausea and gastric discomfort, usually at the beginning of therapy and transient
- In combination with levodopa: enhanced dyskinesias (involuntary movements) possible
- Sleep disturbances or vivid dreams in individual cases
Drug Interactions
In addition to the interactions already mentioned with antidepressants and certain opioids, further interactions are known. Ciprofloxacin, an antibiotic from the fluoroquinolone group, can significantly increase rasagiline blood levels because it inhibits the same metabolic pathway in the liver (CYP1A2). A dose reduction of rasagiline may be necessary in combination with ciprofloxacin. Smoking, on the other hand, accelerates the breakdown of rasagiline via CYP1A2 and may reduce its efficacy.
Rasagiline on Sanoliste
On Sanoliste you will find neurologists who specialise in movement disorders and Parkinson's disease. Expert neurological diagnostics is the first step towards individually tailored treatment planning. Parkinson's disease requires continuous, specialist-supervised treatment that is adapted to the changing needs of patients as the disease progresses.
The content on this page is for general information purposes only. It does not replace consultation with a physician. Rasagiline is a prescription-only medicine and may only be used following medical prescription.
Frequently Asked Questions about Rasagiline
Can rasagiline halt Parkinson's disease?
Rasagiline is approved for the symptomatic treatment of Parkinson's disease. The question of whether rasagiline has neuroprotective effects and slows disease progression was investigated in clinical studies, but did not provide conclusive evidence. The ADAGIO study suggested possible disease-modifying effects, but was unable to prove them definitively. Rasagiline is therefore primarily regarded as a symptomatic medication that can improve the quality of life of Parkinson's patients.
What is the difference between rasagiline and selegiline?
Both active substances belong to the group of selective MAO-B inhibitors. Rasagiline is a more recent development with higher MAO-B selectivity than selegiline. Selegiline is metabolised in the body to metabolites including amphetamine compounds, which may cause unwanted effects such as sleep disturbances. Rasagiline does not have this disadvantage. The dosing of rasagiline is simpler: once daily 1 mg, whereas selegiline must be taken several times daily. Which active substance is more suitable is decided individually by the treating neurologist.
Do I need to avoid certain foods when taking rasagiline?
Non-selective MAO inhibitors require strict dietary restrictions, as tyramine-containing foods such as aged cheese, red wine or fermented products can cause dangerous blood pressure increases. With rasagiline as a selective MAO-B inhibitor, these restrictions are generally not required at therapeutic doses. Nevertheless, some guidelines recommend avoiding excessively high amounts of tyramine-containing foods. The treating physician provides individual recommendations on this.