Safinamide (
INN
Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...
; brand name Xadago) is a
drug used as an add-on treatment for
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ...
with
"off" episodes; it has multiple modes of action, including the
inhibition of monoamine oxidase B.
[ Se]
FDA index page for NDA 207145
for updates.
It was approved in the European Union in February 2015,
[ in the United States in March 2017,][ and in Canada in January 2019.]
Medical uses
Safinamide is used to treat idiopathic
An idiopathic disease is any disease with an unknown cause or mechanism of apparent spontaneous origin. From Greek ἴδιος ''idios'' "one's own" and πάθος ''pathos'' "suffering", ''idiopathy'' means approximately "a disease of its own kin ...
Parkinson's disease as add-on for people taking a stable dose of levodopa (L-dopa) alone or in combination with other Parkinson drugs, to help with "off" episodes when levodopa stops working.[
]
Contraindications
Safinamide is contraindicated in people with severe liver impairment, with albinism
Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes. Individuals with the condition are referred to as albino.
Varied use and interpretation of the term ...
, retinitis pigmentosa
Retinitis pigmentosa (RP) is a genetic disorder of the eyes that causes loss of vision. Symptoms include trouble seeing at night and decreasing peripheral vision (side and upper or lower visual field). As peripheral vision worsens, people may ...
, severe diabetic neuropathy, uveitis
Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and in ...
and other disorders of the retina
The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then ...
. Combination with other monoamine oxidase (MAO) inhibitors and pethidine
Pethidine, also known as meperidine and sold under the brand name Demerol among others, is a synthetic opioid pain medication of the phenylpiperidine class. Synthesized in 1938 as a potential anticholinergic agent by the German chemist Otto Eis ...
is also contraindicated.[
It is not safe for women to take during pregnancy.][ It is excreted in breast milk and the effects on infants are unknown.][
]
Adverse effects
Common adverse events in clinical trials (in more than 1% of people) included nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...
, dizziness, tiredness, sleeplessness, orthostatic hypotension
Orthostatic hypotension, also known as postural hypotension, is a medical condition wherein a person's blood pressure drops when standing up or sitting down. Primary orthostatic hypertension is also often referred to as neurogenic orthostatic hyp ...
(low blood pressure), and headache. There was no significant difference in the occurrence of these effects between safinamide and placebo
A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures.
In general, placebos can af ...
.
In experiments with rats (but not in those with monkeys), retinopathies have been observed.
Overdose
Expected overdose effects are hypertension (high blood pressure), orthostatic hypotension, hallucinations, psychomotor agitation
Psychomotor agitation is a symptom in various disorders and health conditions. It is characterized by unintentional and purposeless motions and restlessness, often but not always accompanied by emotional distress. Typical manifestations include ...
, nausea, vomiting, and dyskinesia
Dyskinesia refers to a category of movement disorders that are characterized by involuntary muscle movements, including movements similar to tics or chorea and diminished voluntary movements. Dyskinesia can be anything from a slight tremor of ...
. In studies, a single person was suspected to have overdosed for a month; symptoms were confusion, drowsiness and mydriasis (dilation of the pupils) and subsided completely after the drug was discontinued. No specific antidote is available.
Interactions
As a MAO inhibitor, safinamide can theoretically cause hypertensive crises
Severely elevated blood pressure (equal to or greater than a systolic 180 or diastolic of 120—sometimes termed malignant or accelerated hypertension) is referred to as a hypertensive crisis, as blood pressure at this level confers a high risk ...
, serotonin syndrome
Serotonin syndrome (SS) is a group of symptoms that may occur with the use of certain serotonergic medications or drugs. The degree of symptoms can range from mild to severe, including a potentiality of death. Symptoms in mild cases include high ...
and other severe side effects when combined with other MAO inhibitors or with drugs that are known to interact with MAO inhibitors, such as pethidine, dextromethorphan
Dextromethorphan (DXM) is a medication most often used as a cough suppressant in over-the-counter cold and cough medicines. It is sold in syrup, tablet, spray, and lozenge forms. In 2022, the FDA approved a formulation of it combined with bu ...
, selective serotonin reuptake inhibitor
Selective serotonin reuptake inhibitors (SSRIs) are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder, anxiety disorders, and other psychological conditions.
SSRIs increase the extracellul ...
s (SSRIs), serotonin–noradrenaline reuptake inhibitors (SNRIs), tricyclic
Tricyclics are chemical compounds that contain three interconnected rings of atoms.
Many compounds have a tricyclic structure, but in pharmacology, the term has traditionally been reserved to describe heterocyclic drugs. Among these are antid ...
and tetracyclic antidepressant
Tetracyclic antidepressants (TeCAs) are a class of antidepressants that were first introduced in the 1970s. They are named after their tetracyclic chemical structure, containing four rings of atoms, and are closely related to the tricyclic ant ...
s. An interaction with tyramine
Tyramine ( ) (also spelled tyramin), also known under several other names, is a naturally occurring trace amine derived from the amino acid tyrosine. Tyramine acts as a catecholamine releasing agent. Notably, it is unable to cross the blood ...
, a substance found in various foods, could be expected by the same reasoning but has been excluded in studies.
Safinamide should not be given with opioids; some fatal reactions have occurred.[
Another theoretical interaction is with drugs with affinity to the transporter protein ABCG2 (also known as BCRP), such as ]pitavastatin
Pitavastatin (usually as a calcium salt) is a member of the blood cholesterol lowering medication class of statins.
Like other statins, it is an inhibitor of HMG-CoA reductase, the enzyme that catalyses the first step of cholesterol synthesis ...
, pravastatin
Pravastatin, sold under the brand name Pravachol among others, is a statin medication, used for preventing cardiovascular disease in those at high risk and treating abnormal lipids. It should be used together with diet changes, exercise, and w ...
, ciprofloxacin
Ciprofloxacin is a fluoroquinolone antibiotic used to treat a number of bacterial infections. This includes bone and joint infections, intra abdominal infections, certain types of infectious diarrhea, respiratory tract infections, skin inf ...
, methotrexate, and diclofenac
Diclofenac, sold under the brand name Voltaren, among others, is a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain and inflammatory diseases such as gout. It is taken by mouth or rectally in a suppository, used by injection, or ...
; a study with the latter has shown no clinical relevance. A study testing possible interactions with amidase
In enzymology, an amidase (, ''acylamidase'', ''acylase (misleading)'', ''amidohydrolase (ambiguous)'', ''deaminase (ambiguous)'', ''fatty acylamidase'', ''N-acetylaminohydrolase (ambiguous)'') is an enzyme that catalyzes the hydrolysis of an am ...
inhibitors is part of the post-authorisation development plan. There are no relevant interactions related to cytochrome P450
Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various co ...
(CYP) liver enzymes, although one inactivation pathway of safinamide seems to be mediated by CYP3A4.
Pharmacology
Mechanisms of action
Like the older antiparkinson drugs selegiline and rasagiline
Rasagiline (Azilect, Azipron) is an irreversible inhibitor of monoamine oxidase-B used as a monotherapy to treat symptoms in early Parkinson's disease or as an adjunct therapy in more advanced cases.
The racemic form of the drug was invented b ...
, safinamide is a selective monoamine oxidase B
Monoamine oxidase B, also known as MAOB, is an enzyme that in humans is encoded by the ''MAOB'' gene.
The protein encoded by this gene belongs to the flavin monoamine oxidase family. It is an enzyme located in the outer mitochondrial membrane. I ...
inhibitor, reducing degradation of dopamine; in contrast to the other two, its action is reversible. Safinamide also inhibits glutamate release and dopamine and serotonin reuptake. It binds to the sigma receptor
Sigma receptors (σ-receptors) are protein cell surface receptors that bind ligands such as 4-PPBP (4-phenyl-1-(4-phenylbutyl) piperidine), SA 4503 (cutamesine), ditolylguanidine, dimethyltryptamine, and siramesine. There are two subtypes, ...
s as well, with IC50 values for binding inhibition of 19 nM for σ1 and 1,590 nM for σ2. Additionally, it blocks sodium and calcium channels, the relevance of which for its antiparkinson action is however unknown.
Pharmacokinetics
Safinamide is absorbed quickly and nearly completely from the gut and reaches highest blood plasma
Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, but contains proteins and other constituents of whole blood in suspension. It makes up about 55% of the body's total blood volume. It is the intr ...
concentrations after 1.8 to 2.8 hours. There is no relevant first-pass metabolism
The first pass effect (also known as first-pass metabolism or presystemic metabolism) is a phenomenon of drug metabolism whereby the concentration of a drug, specifically when administered orally, is greatly reduced before it reaches the system ...
; total bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation.
By definition, when a medication is administered intravenously, its bioavailability is 100%. Ho ...
is 95%. The substance is bound to plasma proteins
Blood-proteins, also termed plasma proteins, are proteins present in blood plasma. They serve many different functions, including transport of lipids, hormones, vitamins and minerals in activity and functioning of the immune system. Other blood p ...
to 88–90%.
The metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...
is not well understood. The principal step is mediated by amidases which have not been identified, and produces safinamide acid (NW-1153). Other relevant metabolites are O-debenzylated safinamide (NW-1199), the N-dealkylated amine which is then oxidized to a carboxylic acid (NW-1689), and the glucuronide
A glucuronide, also known as glucuronoside, is any substance produced by linking glucuronic acid to another substance via a glycosidic bond. The glucuronides belong to the glycosides.
Glucuronidation, the conversion of chemical compounds to glucu ...
of the latter. In tests with liver microsome
In cell biology, microsomes are heterogeneous vesicle-like artifacts (~20-200 nm diameter) re-formed from pieces of the endoplasmic reticulum (ER) when eukaryotic cells are broken-up in the laboratory; microsomes are not present in healthy, liv ...
s, dealkylation seemed to be mediated by CYP3A4, but other CYP enzymes appear to be involved as well. Safinamide acid binds to the organic anion transporter 3 (OAT3), but this has probably no clinical relevance. Safinamide itself transiently binds to ABCG2. No other transporter affinities have been found in preliminary studies.
Safinamide is eliminated, mainly (>90%) in form of its metabolites, via the kidney, with an elimination half-life
Biological half-life (also known as elimination half-life, pharmacologic half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the bl ...
of 20 to 30 hours. Only 1.5% are found in the stool.
History
The compound was originally discovered at Farmitalia-Carlo Erba, which was acquired by Pharmacia
Pharmacia was a pharmaceutical and biotechnological company in Sweden that merged with the American pharmaceutical company Upjohn in 1995.
History
Pharmacia company was founded in 1911 in Stockholm, Sweden by pharmacist Gustav Felix Grönfeldt ...
in 1993. In 1995, Pharmacia merged with Upjohn
The Upjohn Company was a pharmaceutical manufacturing firm founded in 1886 in Hastings, Michigan, by Dr. William E. Upjohn who was an 1875 graduate of the University of Michigan medical school. The company was originally formed to make ''friabl ...
. Safinamide was first disclosed in 1998. In the course of a major restructuring in the same year, all rights for safinamide were transferred to the newly formed company Newron Pharmaceuticals, which developed the drug until it was sold to Merck KGaA
The Merck Group, branded and commonly known as Merck, is a German multinational science and technology company headquartered in Darmstadt, with about 60,000 employees and present in 66 countries. The group includes around 250 companies; the ma ...
in 2006.
In 2007, a Phase III clinical trial
The phases of clinical research are the stages in which scientists conduct experiments with a health intervention to obtain sufficient evidence for a process considered effective as a medical treatment. For drug development, the clinical phases ...
was started, scheduled to run until 2011. In October 2011 Merck, now Merck-Serono, announced that they would give all rights to develop the compound back to Newron because they wanted to prioritise other projects and had corrected their estimates for safinamide's market potential downwards.
The US Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
(FDA) refused to file Newron's application in 2014 on formal grounds. Newron re-applied in December 2014. In spring 2015, following a commercial agreement between Newron and the Italian pharmaceutical company Zambon
Zambon is an Italian company that has been operating in the pharmaceutical and fine chemical industry since 1906. The company is currently run by Elena Zambon who is the daughter of the founder.{{Cite news, url=http://www.repubblica.it/economia/a ...
, the European Medicines Agency (EMA) approved the drug. In the following years, the drug has been launched in several European countries. Safinamide is the first antiparkinson medication to be approved for ten years. Safinamide was approved by US FDA in March 2017 for people with Parkinsons taking levodopa/carbidopa during "off" episodes.
Research
Potential additional uses might be restless legs syndrome (RLS) and epilepsy
Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrica ...
. Safinamide was being tested in Phase II trials in 2008, but no results are available. When used as an adjunct to parkinsonian medication, safinamide was found to be efficacious in reducing pain in PD.
References
External links
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