selective serotonin reuptake inhibitors (SSRIs)
This section is designed to inform professionals.
The first SSRI to become available was fluoxetine (Prozac),which rapidly gained popularity largely because of its improved safety and side effects profiles compared to the tricyclic antidepressants.
The SSRIs are considerably safer in overdose and do not cause the sedation, weight gain or hypotension associated with many of the tricyclics.
The SSRIs, as a class, share several common features but there are also differences and unique aspects to their functioning.
One of the significant pharmacokinetic differences is the length of the half-life of the parent compound and it's main (active) metabolite. The degree of 'withdrawal' symptoms following sudden cessation of the medication tends to be inversely related to it's half-life.
SSRIs and their half-lives
|
Generic Name
|
Brand Name
|
Parent
1/2 life
|
Metabolite
1/2 life
|
Full subsidy
in NZ
|
| Fluoxetine |
Fluox, Prozac |
24-72hr |
4-6days |
Fluox |
| Paroxetine |
Aropax, Loxamine |
20hr |
NA |
Loxamine |
| Citalopram |
Cipramil, Celapram |
33hr |
NA |
Celapram |
| Escitalopram |
Lexapro |
|
|
No |
| Fluvoxamine |
|
15hr |
|
No |
| Sertraline |
Zoloft |
24-26hr |
66 hr |
No |
|
