Questions tagged [pharmacology]
Pharmacology is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function.
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Hi, could someone explain what use-dependence is? And does it differ from one drug type to another? For instance anaesthetics vs anti-epileptics?
I may have understood it incorrectly but I read that in case of local anaesthetics, the use dependence is such that more the number of open sodium channels, more the number of drug molecules entering, ...
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What retrospective analysis happens after a clinical trial fails?
After a failed pharmaceutical clinical trial, what retrospective analyses are typically performed to understand why the drug program failed the trial? For example, are further experiments done to ...
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In drug discovery, what is an undruggable target? [closed]
The term "undruggable" is often use in drug discovery. As far as I understand it, it means "for which no inhibitor has been found so far".
It's a fuzzy, non-satisfying, definition.
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Is there any bloodstream chemical composition software simulator?
Let's say I'd like to know how certain substance affects bloodstream levels of certain drug during a period of time. Is there any simulation software available publicly to run such kind of simulation?
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Mechanism of oral fluoride ion absorption
What is the mechanism by which F- ions are absorbed by the body when ingested? Is absorption due to conversion to hydrogen fluoride by the action of stomach acid and then subsequent diffusion across ...
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drug-dna concentration
I want to understand how you calculate the final concentration of a Drug-DNA complex. I tried to mix equal concentration and volume of drug and DNA to form a complex and tried to see the absorbance ...
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How do you calculate the time until the steady-state of a drug?
I encountered a mathematically intriguing conundrum, in that it's related to medicine but is centered around mathematics.
Suppose drug A has a half-life in the body of 30 hours. The patient takes 40mg ...
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Why are there so many carbonic anhydrase structures in the Protein Data Bank?
I've been looking through PDB — the Protein Data Bank — and I noticed that the protein with the most structures is human carbonic anhydrase II (UniProt: P00918), with over a thousand X-ray structures.
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Bioavailability -- what is the effect of absorption rate?
I learnt about Bioavailability and this is the definition given by many sources:
...the fraction (%) of an administered drug that reaches the systemic circulation.
(https://en.m.wikipedia.org/wiki/...
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Does ellagic acid dissolved in DMSO react with Brain Heart Infusion media?
I dissolved 2mg of Ellagic acid in 500 microliter of DMSO. I used 100 microliters of this solution to test for antimicrobial susceptibility against E.faecalis by adding it to 100 microliters of BHI ...
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PEGylation safety and hybridomas
PEGylation is the covalent attachment of PEG (PolyEthylene Glycol) to molecules (e.g. proteins). It states in wikipedia ("PEGylation"):
The covalent attachment of PEG to a drug or ...
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How does hypokalemia antagonize lidocaine's effect?
I was reading the lidocaine user's manual for dentistry use and according to it and I quote "Lidocaine in concomitant use with acetazolamide, thiazides and loop acting diuretics. The hypokalemia (...
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Why are drug dosages so high in some mice studies?
On reading through some research on the effects of certain drugs I often come across staggeringly high dosages such as in this paper:
Römer, B., Pfeiffer, N., Lewicka, S., Ben-Abdallah, N., Vogt, M. ...
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What Produces the Postive Potenial in the lumen of the thick ascending loop of Henle?
In the Thick Ascending Loop of Henle, Paracellular diffusion of certain Solutes like magnesium and calcium takes place. Such diffusion is a result of the positive lumen potential.
Looking at the image ...
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how to perform ligand and DNA alignment in pymol
I need help in inserting ligand to specific base pair in DNA. I have a drug molecule and want to insert in between the base pairs I am interested in (it is dsDNA). Please note that it is a customed ...
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Difference between IC50 and Michaelis-Menten constant
I am new to biology, and getting to know the term IC50, I found that there is a connection between IC50 and Michaelis-Menten constant by the Cheng-Prusoff equation
$K_{i}=\frac{\mathrm{IC}_{50}}{1+\...
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Why does the Scatchard plot have a negative gradient?
I am very confused as to why the scatchard plot has a negative gradient. If the x axis shows increasing B, specific binding to a receptor, and on the y axis the specific binding (B)/concentration of ...
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Calculation of drug efficacy- mathematical biology approach
I am participating in a mathematical biology project.
I would like to discuss the following problem:
Let A be a drug such that $x_{o}$ chemical units of it kills 12% of $y$ cells per 1 day, I would ...
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What is the physical dimension of international unit (IU)?
I was skimming through a study [mRNA-based COVID-19 vaccine boosters induce neutralizing immunity against SARS-CoV-2 Omicron variant, page 6, figure 3(A)] on vaccine and I came across the ...
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Meaning of "acute LSD"
I am currently reading this research paper: https://www.nature.com/articles/1395848, and I'm confused by this line: "Serotonin Receptor mRNA Levels Are Unchanged by Acute LSD".
What is the ...
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What specific interaction between methylphenidate and quetiapine causes toxicity concerns?
A number of reputable sources on drug interactions posit a potential interaction between methylphenidate and quetiapine, described on Medscape as follows:
quetiapine increases toxicity of ...
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What mechanism causes the presence of photosensitizers in mitochondria to change membrane ionic currents?
In the original question, the article in question was talking about specifically about this compound, Benzoporphyrin:
Characterization of Perturbing Actions by Verteporfin, a Benzoporphyrin ...
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Is it advised to calculate QED parameters for salts?
QED (quantitative estimation of drug-likeness) is a score which helps you to predict if a small molecule is desirable as an orally absorbed drug, described in the Quantifying the chemical beauty of ...
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Medical Physiology
I've come across the topic of the influence of inhaled ammonia (caustic ammonia) on breathing rate and some cardiovascular changes. All of this stuff is thought to be mediated through the fifth ...
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What determines if a compound is primarily uptaken by the lymphatic extensions rather than the portal vein blood supply in villi of the intestine?
I am currently studying the intestinal absorption/transport systems, but confused about one part specifically. There are hydrophilic and lipophilic compounds (to varying degrees), and they get ...
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If blood vessels mostly aren't supplied by parasympathetic nerves, how effects through M3-ACh receptors are mediated?
Blood vessels throughout the body mostly aren't supplied by any parasympathetic fibres. But the effects of ACh through M3-ACh receptors would infact release NO (which acts on VSM and causes ...
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How easy is it for quantum dots to enter the intracellular portions of cells?
As quantum dots have better quantum yield than organic dyes, many are being developed as a substitute for them. Nonetheless, could these substitutes be small enough to enter inside cells as current ...
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Why do the mRNA vaccines for COVID need special lipids?
I've read that the Pfizer mRNA vaccine is delivered to the cell by encapsulating the fragile mRNA into a lipid nanoparticle. However, the lipid has to be PEGylated in order to avoid immunogenecity. ...
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Concentration of active ingredient
For some time now, I have been wondering why, when a tablet is taken, the concentration of active ingredient undergoes an exponential decrease after the maximum concentration value in the blood is ...
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Why does warfarin decrease biological activity of protein C?
Warfarin inhibits VKOR. Hence it disrupts vitamin K dependent $\gamma$-carboxylation of Fc- II, VII, IX, X.
But what exactly it does to Protein C and Protein S? How does it also affect anticoagulant ...
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Can you find the mass of drug X remaining in the body after an oral dose with only bioavailability and half-life?
I'm reviewing this question and think you can't find the answer with the information given.
A patient receives 1g of drug X as a single oral dose. Drug X has a
half-life of 12 hours and an oral ...
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Does one wing of fly contain harmful microbes and the other contain only antibodies? [closed]
There was this study but the conclusion and it's source's relability seemed a bit off. How come a house flies one wing contain all microbe and the other don't.
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What is the purpose of an siRNA screen in drug discovery?
In the paper "A genome-wide siRNA screen identifies a druggable host pathway essential for the Ebola virus life cycle" by Martin et al. the authors try to disrupt the Ebola life-cycle by ...
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Why do animal cells "mistake" rubidium ions for potassium ions?
So, I was browsing the Wikipedia article for rubidium, and came across this interesting tidbit:
Rubidium is not a known nutrient for any living organisms. However, rubidium ions have the same charge ...
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How do prodrugs exactly work? Are there multiple varieties of prodrugs?
I have been reading about a (new?) prodrug of LSD, 1CP-LSD, which is being synthesized in the body to LSD.
However, I don't know how exactly. I read somewhere, that another prodrug of LSD, 1P-LSD was ...
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Does LSD "stay" in your fat storage and then "returns" back?
This rumor was told me by a very anti-drug person. A stance I agree with only lightly.
The rumor was that when you take LSD, it stores itself in your fat storage, and then returns back in 3-6 months, ...
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Could a vaccine injecting B cells theoretically work?
So I was in the car riding to school today when I was struck with genius. Each B cell is attuned to a different pathogen, am I correct? By that logic, would a vaccine injecting a dose of B cells ...
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Are drugs made bitter artificially to prevent being mistaken for candy?
All drugs I remember tasting (with the notable exception of Aspirin) have bitter taste. Is the taste due to the active substance, or is a bittering agent added to them, perhaps to prevent overdose?
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How exactly does chemotherapy cause anemia?
I’ve been trying to figure this out for the past few hours but I still can’t find something as in depth as I’m looking for. So far all I’ve found is that chemo drugs kill bone marrow cells and some ...
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What degree of influence do SNPs have on activity of ligands at receptors?
I know that generally, evolution tends to evolve towards having some wiggle room in respect to effect of polymorphisms on binding of endogenous ligands, but with synthetic ligands, especially modern ...
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Does GABA enhance or inhibit negative effects of glutamate? [closed]
A study on NCBI studied the correlation between a depressive mood and chronic pain. I researched this because today I noticed unusual emotional volatility as a result of 2 days of acute back pain ...
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Why do beta-1 and beta-2 adrenergic receptors result in two completely different effects (though both use Gs pathway)?
$\beta_2$ adrenergic Receptors are $G_s$-coupled 7-TM proteins. Considering that $G_s$ , by activation increases $[\text{cAMP}]_\text{cytosol}$ which inhibits MLCK of smooth muscles (and causes ...
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Can severe vasoconstriction increase systolic blood pressure?
I know that, vasoconstriction results in increased total peripheral resistance which is responsible for the rise in diastolic blood pressure. Also, cardiac output is responsible for the systolic blood ...
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How does noradrenaline result in rise of systolic blood pressure even when the cardiac output is decreasing?
Systolic blood pressure[SBP] depends on the cardiac output. When Nor adrenaline is given there is vasoconstriction due to alpha-1 action on blood vessel, vasoconstriction results in increased total ...
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Is there an antidote for caffeine, e.g. as a supplicant for caffeine-intolerant persons?
First, let me state I'm not talking about a medical emergency. No one is in a serious condition.
My girlfriend is, we think, caffeine-intolerant. She loves the smell of coffee and the habit of coffee ...
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Why is prothrombin time used to monitor warfarin and not activated partial thromboplastin time?
Warfarin is said to change prothrombin time (PT) but not activated partial thromboplastin time (aPTT) (for practical purposes at least anyways, not really sure). But looking at the mechanism of action ...
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Area under the curve in a drug concentration curve
I am not from a background on pharamacokinetics and trying to learn some concepts.
I noticed that the definition for AUC involve the first 24 hours. For example in here AUC is defined as "the area ...
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Same target receptor different mechanism of action?
If different drugs have the same receptor as a target, does that imply that they have the same mechanism of action?
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Why is ACE2 not used as drug against covid? [closed]
Can ACE2 be produced and used as drug against covid? I read it is the receptor molecule. If it is in the organism the virus should bind to it and could not attack cells anymore? Is that right?
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Why do the calicheamicins bind to DNA at the minor, rather than the major, groove?
I am trying to understand why some drugs bind only to the minor groove and not to the major groove. More specifically, I am interested in calicheamicins.
They target DNA and cause strand scission. ...
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