atypical antidepressant
An atypical antidepressant is any antidepressant medication that acts in a manner that is different from that of most other antidepressants.
Atypical antidepressants include:
* agomelatine
* bupropion
* iprindole
* opipramol
* tianeptine
* ...
with additional
anxiolytic
An anxiolytic (; also antipanic or anti-anxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxie ...
properties acting via
dopaminergic
Dopaminergic means "related to dopamine" (literally, "working on dopamine"), a common neurotransmitter. Dopaminergic substances or actions increase dopamine-related activity in the brain.
Dopaminergic pathways, Dopaminergic brain pathways facil ...
and
serotonergic
A serotonergic substance, medication, or receptor protein is one that affects neurotransmission pathways that involve serotonin, as follows:
* Serotonergic drugs
** Serotonin receptor agonists
** Serotonin receptor antagonists
** Serotonin reupta ...
mechanisms which was formerly marketed in
France
France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...
and
Spain
Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...
, as well as
Morocco
Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...
. The drug was first introduced in France sometime around 1990. It was withdrawn from the market in 1999 (Morocco) and 2000 (France) following incidences of
hepatotoxicity
Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury (DILI) is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdr ...
.
Pharmacology
Pharmacodynamics
Medifoxamine has been found to act preferentially as a relatively weak
dopamine reuptake inhibitor
A dopamine reuptake inhibitor (DRI) is a class of drug which acts as a reuptake inhibitor of the monoamine neurotransmitter dopamine by blocking the action of the dopamine transporter (DAT). Reuptake inhibition is achieved when extracellular dop ...
, but also as an even weaker
serotonin reuptake inhibitor
A serotonin reuptake inhibitor (SRI) is a type of drug which acts as a reuptake inhibitor of the neurotransmitter serotonin (5-hydroxytryptamine, or 5-HT) by blocking the drug action, action of the serotonin transporter (SERT). This in turn lea ...
antagonist
An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.5-HT2A and 5-HT2C receptors (IC50 = 950 and 980, respectively; notably greater
affinity
Affinity may refer to:
Commerce, finance and law
* Affinity (law), kinship by marriage
* Affinity analysis, a market research and business management technique
* Affinity Credit Union, a Saskatchewan-based credit union
* Affinity Equity Pa ...
relative to
amitriptyline
Amitriptyline, sold under the brand name Elavil among others, is a tricyclic antidepressant primarily used to treat major depressive disorder, and a variety of pain syndromes such as neuropathic pain, fibromyalgia, migraine and tension headac ...
and
imipramine
Imipramine, sold under the brand name Tofranil, among others, is a tricyclic antidepressant (TCA) mainly used in the treatment of depression. It is also effective in treating anxiety and panic disorder. Imipramine is taken by mouth.
Common s ...
). It is known to produce two
active metabolite
An active metabolite, or pharmacologically active metabolite is a biologically active metabolite of a xenobiotic substance, such as a drug or environmental chemical. Active metabolites may produce therapeutic effects, as well as harmful effects. ...
s during
first-pass metabolism
The first pass effect (also known as first-pass metabolism or presystemic metabolism) is a phenomenon of drug metabolism at a specific location in the body which leads to a reduction in the concentration of the active drug before it reaches the ...
in the
liver
The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...
, CRE-10086 (N-methyl-2,2-diphenoxyethylamine) and CRE-10357 (N,N-dimethyl-2-hydroxyphenoxy-2-phenoxyethylamine). The IC50 values of CRE-10086 for
serotonin transporter
The serotonin transporter (SERT or 5-HTT) also known as the sodium-dependent serotonin transporter and solute carrier family 6 member 4 is a protein that in humans is encoded by the SLC6A4 gene. SERT is a type of monoamine transporter protein t ...
, 5-HT2A, and 5-HT2C binding are 450 nM, 330 nM, and 700 nM, respectively, while those of CRE-10357 are 660 nM, 1,600 nM, and 6,300 M. Medifoxamine and its metabolites lack affinity for other
serotonin receptor
5-HT receptors, 5-hydroxytryptamine receptors, or serotonin receptors, are a group of G protein-coupled receptor and ligand-gated ion channels found in multiple tissues including the central and peripheral nervous systems. They mediate both ex ...
s including 5-HT1A, 5-HT1B, 5-HT1D, and 5-HT3 (>10,000 nM). As medifoxamine is metabolized extensively in the liver during first-pass metabolism, and as these metabolites have as much as 3-fold greater activity relative to medifoxamine, it is likely that they contribute significantly to the
pharmacology
Pharmacology is the science of drugs and medications, including a substance's origin, composition, pharmacokinetics, pharmacodynamics, therapeutic use, and toxicology. More specifically, it is the study of the interactions that occur betwee ...
of the parent drug.
Effectiveness and tolerability
Unlike many
tricyclic antidepressant
Tricyclic antidepressants (TCAs) are a class of medications that are used primarily as antidepressants. TCAs were discovered in the early 1950s and were marketed later in the decade. They are named after their chemical structure, which contains ...
s, medifoxamine lacks
anticholinergic
Anticholinergics (anticholinergic agents) are substances that block the action of the acetylcholine (ACh) neurotransmitter at synapses in the central nervous system, central and peripheral nervous system.
These agents inhibit the parasympatheti ...
and
alpha blocker
Alpha blockers, also known as α-blockers or α-adrenoreceptor antagonists, are a class of pharmacological agents that act as antagonists on α-adrenergic receptors ( α-adrenoceptors).
Historically, alpha-blockers were used as a tool for p ...
properties (very low affinity for the
muscarinic acetylcholine receptor
Muscarinic acetylcholine receptors (mAChRs) are acetylcholine receptors that form G protein-coupled receptor, G protein-coupled receptor complexes in the cell membranes of certain neurons and other Cell (biology), cells. They play several role ...
s and 10-fold lower affinity for the α1-adrenergic receptor relative to 5-HT2 binding sites), and is also apparently inactive as a
norepinephrine reuptake inhibitor
A norepinephrine reuptake inhibitor (NRI, NERI) or noradrenaline reuptake inhibitor or adrenergic reuptake inhibitor (ARI), is a type of drug that acts as a reuptake inhibitor for the neurotransmitters norepinephrine (noradrenaline) and epinep ...
(although the same source stating this also states that it is inactive as a serotonin reuptake inhibitor, which was subsequently found not to be the case). Studies in mice revealed that the drug does not possess any
sedative
A sedative or tranquilliser is a substance that induces sedation by reducing irritability or Psychomotor agitation, excitement. They are central nervous system (CNS) Depressant, depressants and interact with brain activity, causing its decelera ...
or locomotor stimulant effects. In accordance with all of the preceding, medifoxamine was found to be well tolerated at dosages of 100–300 mg per day in
clinical trial
Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...
s.
Double-blind
In a blind or blinded experiment, information which may influence the participants of the experiment is withheld until after the experiment is complete. Good blinding can reduce or eliminate experimental biases that arise from a participants' expec ...
clinical studies
Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietar ...
have found it to have similar effectiveness to imipramine,
clomipramine
Clomipramine, sold under the brand name Anafranil among others, is a tricyclic antidepressant (TCA). It is used in the treatment of various conditions, most notably obsessive–compulsive disorder but also many other disorders, including hyper ...
, and
maprotiline
Maprotiline, sold under the brand name Ludiomil among others, is a tetracyclic antidepressant (TeCA) that is used in the treatment of depression (mood), depression. It may alternatively be classified as a tricyclic antidepressant (TCA), specific ...