Well, if medications had more unique names wouldn't hurt either. Two separate antidepressants: Escitalopram and Citalopram. And pronounced, they sound almost the same as well.
The names only sound confusingly similar to people unfamiliar with them - for physicians and pharmacists, it's rare to confuse them.
The similarity in the names is actually intentional and a feature. For example, erythromycin and azithromycin have the same suffix and similar prefixes, which is an indicator that, not only do they belong to the same class, but one is a derivative of the other.
It's been a while since I studied this, but based on the names alone, I would be willing to bet that Escitalopram is an S-enantiomer of Citalopram - ie, a mirror image of the drug (or an isolation of one of the two mirror images present in the latter). If you say it out loud, it's almost a mnemonic pun.
I could also guess that's an SSRI based on the "pram" suffix, though admittedly you made that easier by mentioning it was an antidepressant in the first place.
INN names (like citalopram) are actually incredibly well-designed for the intended user (a pharmacist or physician, not a patient). I wish engineering terms had the same level of consistency.
Edit: Turns out I was right. Both are SSRIs, and the former is the S-enantiomer of the latter.
Not exactly. You're right that escitalopram is the S-enantiomer; citalopram is the racemic mixture of R- and S-enantiomers (of which only S- has the antidepressant effect).
The racemic mix usually has a slightly higher level of side effects.
Possibly: the process to manufacture the molecules is also patented, and you must make the racemic mix to extract the active enantiomer. Not sure though.