At higher doses however, maprotiline increases serotonergic transmission and increases the level of serotonin available. Pharmacokinetics
After oral use absorption is good. It binds to plasma proteins 80–90%. Maximal plasma concentration is reached 6 hours after use. The mean time to peak is 12 hours. The terminal half-life of averages 51 hours. Chemistry
Maprotiline is a tetracyclic compound and is grouped with the TeCAs. Its chemical name is N-methyl-9,10-ethanoanthracen-9(10H)-propylamine. The drug has a dibenzobicyclo[2.2.2]octadiene (9,10-dihydro-9,10-ethanoanthracene) ring system; that is, a tricyclic anthracene ring system with an ethylene bridge across the central ring. This results in it having a unique three-dimensional central ring (a bicyclo[2.2.2]octane or 1,4-endoethylenecyclohexane ring) and being a tetracyclic rather than a tricyclic compound. However, it could also or alternatively be considered to be a tricyclic and hence a TCA. In addition to its heterocyclic ring system, maprotiline has an alkylamine side chain attached similarly to other TCAs (but notably unlike other TeCAs). In terms of the side chain, it is a secondary amine, and its chemical structure, aside from the ethylene link in the central ring, is similar to that of secondary amine TCAs like nortriptyline and protriptyline. In accordance, the pharmacology of maprotiline is very similar to that of secondary amine TCAs.Maprotiline is very similar in structure to the anxiolytic, sedative, and muscle relaxant drug benzoctamine (Tacitin). The only structural difference between the two compounds is in the length of their side chain. However, this modification results in considerable differences in their pharmacological and therapeutic effects.
Rothmund–Thomson syndrome (RTS) is a rare autosomal recessive skin condition. There have been several reported cases associated with osteosarcoma. A hereditary basis, mutations in the DNA helicase RECQL4 gene, causing problems during initiation of DNA replication has been implicated in the syndrome. Signs and symptoms
Sun-sensitive rash with prominent poikiloderma and telangiectasias
Juvenile cataracts
Saddle nose
Congenital bone defects, including short stature and radial ray anomalies such as absent thumbs
Hair growth problems (absent eyelashes, eyebrows and/or hair)
Hypogonadism has not been well documented
Hypodontia
Calcium problems (not documented in journals)
Ear problems (not documented in journals but identified by patients in support groups)
Produces osteosarcomaThe skin is normal at birth. Between 3 and 6 months of age, the affected carrier develops poikiloderma on the cheeks. This characteristic "rash" that all RTS carriers have can develop on the arms, legs and buttocks. "Poikiloderma consists of areas of increased and decreased pigmentation, prominent blood vessels, and thinning of the skin." Accelerated aging
In humans, individuals with RTS, and carrying the RECQL4 germline mutation, can have several clinical features of accelerated aging. These features include atrophic skin and pigment changes, alopecia, osteopenia, cataracts and an increased incidence of cancer. Also in mice, RECQL4 mutants show features of accelerated aging. Causes
RTS is caused by a mutation of the RECQL4 gene, located at chromosome 8q24.3. The disorder is inherited in an autosomal recessive manner.