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Why do some drugs take longer to kick in..

rickolasnice

rickolasnice

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Dunno if this is ADD material (probably not) but i thought i'd get a quick, CORRECT answer here.. rather than people guessing elsewhere..

Title says it all: Why do some drugs take longer to work than others? (Oral administration)

Phenibut, aMT, 6-APB, DOx, etc all seem to take 3 hours..

Why 3 hours?

Most others; Amphetamines, MDMA, etc all seem to take about 30 minutes..

This 1 i understand..

But why longer for others and what is it about the 3 hour mark?
 
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6apb kicks in wayyyy quicker than three hours.

really there is no magic explanation, some drugs just take longer to have effect. maybe because the effects need to build to a certain level before they become desirable and this can take a widely varying amount of time. believe me they do work before this time period you just dont notice them up until then.
 
^ I would have thought, then, that taking a double dose would almost half the come up time?
 
rickolasnice said:
^ I would have thought, then, that taking a double dose would almost half the come up time?
Click to expand...

it does with crack/ritalin/cocaine/cannabis- dopaminergics

mdma/amt/6apb/mda not as much as serotonergic dominant drugs always seems to have a lag and take longer to reach a peak.

this has been my experience though it may be entirely subjective
 
Different drugs have different hydrophilic and lipophilic properties contributing to a wide range of possibilities as it goes into your digestive tract. The ability for a drug to cross into the blood stream will be different depending on the chemical structure. If a substance for example wants to passively diffuse through the membranes, it must have a degree of duel solubility. The movement across the membrane is promoted by the difference in concentration gradient across the membranes. However, with out any lipophilic characteristics, passive diffusion wont happen. Same goes for no hydrophilic characteristic. Another possibility may be some sort of transport system. Some molecules are to hydrophilic to participate in passive diffusion, and are sometimes seen to be taken in through an active transport system. These transport systems can vary in the type molecule who can serve as substrate for the mechanism. There are also other varying ways a drug can be absorbed into the blood, like pinocytosis, or paracellular absorption. It really depends on the chemical composition/structure of the molecule, as the dictates it's behavior when in our control systems. The acidity or basicity of a drug can make a difference on when, where, and how a drug is take up in to the blood stream. A drug who is weak base, taken in the stomach, will have minimal absorption due to the high pH. Ionized molecules have less to no lipophilic character, preventing diffusion. A drug who is a weak acid will become protonated with n acidic environment gaining a lipophilic characteristic (neutral molecule) aiding in absorption. As you go down the digestive tract the pH becomes more basic till it become a pH of 8 in the colon, becoming a more suitable environment for drugs who are basic. In the intestines there also another altering factor to the absorption rate, the villi that exist, increasing surface area (greater room for absorption), and the villi lack the hydrophilic/lipophilic discriminatory properties allowing for a increased total absorption of molecules who have a poor diffusion tendency, or the basic drugs not well absorbed with in the stomach. The complex molecular structures with in the body create a wide array of negative and positive changes in the pharmacokinetics of the drug with in the body.

Bioavaliability differences be due to potential factors causing incomplete absorption, decomposition in the process of absorption, first-pass metabolism, poor or slow distribution through the body, varying compositions of substrates the drugs carries (pills), etc. Look at DMT, it has little to no diffusion over the BBB due to it's metabolism before it has the ability to produce psychoactive effects. Also the binding of drugs to proteins or what not with in the blood stream, can decrease or increase the concentration of drugs do to displacement from proteins.

My knowledge basis is limited so, I am not getting on the whole picture.
 
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My layman's (rough) understanding it this:

If you sniff coke, it goes straight into the bloodstream and from there into the brain.

However if you eat a drug (like a cannabis cake) it will be digested, so the time it takes to act is at least the time it takes to be absorbed from the gut into the bloodstream. Also, with some drugs it is not the drug itself but a metabolite that is active, so the drug has to be 1) absorbed from the digestive system and 2) processed by the liver to yield the active metabolite before it has a chance to act.
 
^ Yeah thanks but i was talking about oral administration of drugs that don't need to be metabolised to become active ;)
 
Heres something i found on another forum about this very topic

Awhile back, Shulgin performed some positron tests down in Donner Lab, Berkeley. He was working with DOI or DOM I believe. I cannot remember exactly. It too, as many of the DOx structures, takes several hours for onset. Well, he stuck a Fluorine-19 on it, and the subject went under the PET, and what did he find.

It turns out that the said compound did not go straight from the gut, to the liver, blood stream, and finally bbb as most do. Instead! It went to the lungs and the radioactive isomer stayed in the subjects lungs for several hours before finally descending into the brain. Now, the lungs are also responsible for various decompositions and filtering of compounds, just like the liver is, just not the key player. So he hypothesized, that it must of gone to the lungs, then over a period of time(2-3 hrs) was converted to another compound. This then new compound, went into the brain.
Click to expand...
 
Interesting too how the salt form can make for a surprisingly different experience as well due to the how fast or slow it is absorbed. Case in point being MDMA HCl vs. MDMA citrate. I thought the early reports of subjective differences were due to the power of suggestion and were bullshit until running some experiments. MDMA citrate is absorbed a bit slower, and really changes the nature of the experience. Not as rushy coming up, lasts longer, and the comedown was very different....much smoother, and totally lacking the "Oh shit" moment where you feel the ground drop out from beneath you as you come down. Very strange.
 
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Awhile back, Shulgin performed some positron tests down in Donner Lab, Berkeley. He was working with DOI or DOM I believe. I cannot remember exactly. It too, as many of the DOx structures, takes several hours for onset. Well, he stuck a Fluorine-19 on it, and the subject went under the PET, and what did he find.
Click to expand...
Probably DOI, and probably a radioisotope of iodine.
 
Many different factors come into play. The molecule itself of the drug in question, your diet, your nutrion, your weight, your age, your gender, etc.. the variables just go on and on.

Today, a dose of 30mg oxycodone kicked in after a mere 17 minutes, and it kicked in HARD -- when sometimes it has taken oxy as long as 60-70 minutes to kick in for me.

Honestly, today my oxy kicked in faster than it would have if I had snorted it.

However, I attribute this short onset to two other medicines I had taken: aspirin and ginkgo biloba.
The aspirin had thinned my blood, and the ginkgo biloba had increased the circulation to the blood vessels in my upper gastrointestinal tract -- resulting in a rapid absorption of the oxycodone.


Here's a real brain buster for you prodigies at Advanced Drug Discussion:
Why do SMALLER doses of oral d-amphetamine kick in FASTER than larger doses? This is just in my personal experience but I think it has a logical answer
 
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Are you sure it doesn't?
Not even when the chemical in question is known to constrict blood vessels upon physical contact?
 
Cloudy said:
rate of absorption doesn't change due to concentration.
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I've found this to be untrue with certain drugs.. MDMA for example.. a high dose will kick in faster than a low dose.. i once dosed a stupidly high amount and could feel it started to work about 5 - 10 minutes after whereas a normal dose for me would take 20 - 30 minutes to start taking affect.
 
A high dose acting quicker than a low dose is no argument; subjective effects are a universal truth.

However the principle sought to be defended I agree with: Interference with the BBB; multiple disparate substance crossing it, actually has been shown to reduce the threshold, allowing more variegated chemical types through more readily than otherwise; weakening the immune type groundwork of the BBB. Don't ask me to cite but I'm sure there's another here having read the same; somewhere here I believe is where I found such information.
 
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