Pharmaceuticals’ info on Medication is always generic.

Pharmaceuticals will never disclose specific details to consumers and doctors for marketing purposes, most notably Meds-lifespan.
Patients are the first to acknowledge, after few weeks, what professionals don’t say, to their dismay.

There’s no such general consensus on the duration of medications.
Doctors know it.

The lifespan of meds as indicated by manufacturers, is calculated  ‘on body at rest’ and always averaged.
It is mostly unlikely that someone will take a medication in a state of wellbeing.

The current trend in psychopharmacology is XR, as in Extended Release.
XR is calculated in 12 hours, though in real life, the compound is often metabolized within 10 to 6 hours.
This is what defines  “Resistance”, a synonym of Metabolism.

There are hundreds factors affecting Metabolism however, let’s not overlap reactions.
Metabolism is the body Absorbing process of food, vitamins, minerals, medications… its timing varies in each individual.

Stress speeds up metabolism dramatically, the body desperate reaching-out for energy in all directions, last but not least, medication.

I see Tolerance as a bypass of Resistance, not Addiction.
When we get the full benefits of a substance, we don’t develop Tolerance.

I hear all the time from patients: “My medication stopped working”, in contrast to “I’ve been on the same med for 20 years and it works like the first day”.
Since we’re focusing on Mental Health, I ll describe the latter comment as in Mood-Stabilization, hardly achievable for working people in our constant challenging society, though not impossible.
Stable Mood is the criteria used by pharmaceuticals in order to set a med’s active status.
This is very misleading to individuals in leadership positions or students facing challenges on a regular basis. There are ordinary days when meds last longer, or hectic times when they don’t work at all. 
Cortisol and Adrenaline are the main culprits for pushing Metabolism into overdrive.

With that said, what’s the remedy?

Antipsychotics are the only compounds known to slow down Metabolism with side-effects like Weight-gain and Sedation.

More research is needed.

My takeaway is adjusting dosage according to situations.