Category Archives: Science and Research

What are the dangers of taking Mucinex DM and Tylenol simultaneously?

Taking guaifenesen and dextromethorphan (Mucinex DM) with acetaminophen (Tylenol) should not pose a risk of drug-drug interactions, since the metabolism (clearance) of these products do not directly interfere with each other:

Guaifenesin/Guaiphenesin

Use as expectorant (thins mucus to make cough productive)
Metabolized via hydrolysis: Unknown if metabolism via liver enzyme cytochrome P450 (CYP450)
Dextromethorphan

Use as a cough suppressant (anti-tussive) and pseudobulbar affect (uncontrolled crying/laughing)
Metabolized via liver, CYP450 2D6
Acetaminophen/Paracetamol

Use to reduce fever and pain
Metabolized via liver, CYP450 2E1
The main dangers in these medications have to do with excessive concentration of the drug in your body, i.e. overdosing.

Overdosing on dextromethorphan causes breathing problems including no breathing, blurred vision, coma, hallucinations, gastrointestinal spasms (see Dextromethorphan overdose: MedlinePlus Medical Encyclopedia).

Overdosing on acetaminophen causes liver damage serious enough to require transplantation or result in death. You should not take more than 4 grams or 4000 mg per day. Brand name Tylenol comes in doses of 500mg each pill or caplet, which means you should not take more than 8 pills or caplets per day. If you take 2 pills or caplets each dose, you can only take 4 two-pill doses each day to stay on the safer side of liver damage.

Fortunately, guaifenesin toxicity is relatively low, but doses for an adult should not exceed 2400mg per day.

Mucinex DM comes in “regular” and “maximum” strength. Regular strength contains 30mg dextromethorphan hydrogen bromide (HBR) and 600 mg guaifenesin, which you can take 1 or 2 pills (2 pills yield 60mg dextromethorphan 1200mg guaifenesin) every 12 hours. Maximum strength contains 60 mg dextromethorphan and 1200mg guaifenesin, which you can take 1 tablet every 12 hours.

Source: Cough & Chest Congestion Medicine | Mucinex®

You can calculate which is cheaper, by buying either maximum strength and taking 1 pill every 12 hours, or regular strength but taking 2 pills every 12 hours. People tend to prefer swallowing 1 pill versus 2 or more, so less pills per dose is better for patient compliance.

Killing Zika Virus Carrying Mosquitoes with Gene Drives?

Genetically engineering out the lives of pests is not a new idea. The idea of leveraging sexual reproduction to pass specific gene changes (mutations or alterations) through entire populations to control pests has been proposed as far back as the 1940s, for example, A Strain of the Mosquito Aedes aegypti Selected for Susceptibility to the Avian Malaria Parasite Plasmodium lophurae.

Evolutionary geneticist Austin Burt was credited with the method of cutting DNA to reduce populations of disease-spreading species and the associated idea of “Gene drives”. The central idea behind a gene drive is to ensure that the engineered module stands a high probability of being passed onto offspring, such that the genetic module can be spread through the population. We can “drive” a genetic mutation into an entire population.

“How do we do this?”

Imagine if we can genetically engineer the virulence out of mosquito bites — nay, let’s engineer the future lives out of an entire species of the worst offenders (these would be the aegypti mosquitoes) — and free our communities of chemical pesticides! Kill the pests but spare our environment!

That is what Oxitec is working on. The company is harnessing a pathway that has been explored for killing cancer cells to genetically engineer male aegypti mosquitoes. Male aegypti mosquitoes live long enough to mate with female aegypti mosquitoes in the wild. Males pass along what amounts to a ticking time bomb genetic sequence to their female partners. Their offspring will then carry these gene sequences that produce death-causing proteins.

Female aegypti mosquitoes are the ones that bite and deposit diseases in hosts. Thus rather than working on fatality-causing mutations where an aegypti mosquito embryo won’t even see the light of day, Oxitec wants the males mosquitoes to mate with the existing biting wild female population. Offsprings will die before adulthood due to the inherited vulnerability or will be too weak to survive the normal assaults of nature.

“Should we do this? How far should we do this?”

Along with questions of possibility and feasibility comes questions of ethics and responsibility.

What are the ethics of genetically extinguishing entire species, even if we’re talking about a loathed species like the aegypti mosquitoes? You will hear bioethicists talk about the impact on the natural food web and the ripple effect of employing such technology (i.e. “Today, mosquitoes. Tomorrow, other species maybe even certain humans?”)

Additionally, one can argue that the very situations fertile for cultivating diseases are not fixed by genetically fixing pests. How does genetically engineering mosquitoes fix the slums and ghettos in which pests and disease carrying insects establish and thrive? How do we know that another species won’t take the place of one that we genetically extinguished, because the very conditions of poverty remain?

Questions about genetically engineering away virulence and pestilence are complex, and reach beyond what is merely scientifically possible.

We need to consider the law of unintended consequences, and these are complex questions of consequences that are difficult for us to imagine, until we’ve done it.

Then, do we do it? Should we do it?

Antibiotic Resistance: Cultural Issue not Medical Science

We must tackle a cultural problem around overuse of antibiotics.

It doesn’t matter whether we keep coming up with antibiotics: we simply breed for the most drug resistant pathogens by increasing the selective pressure in bacteria. We do this by over-prescribing antibiotics.

But wait. This isn’t necessarily about getting doctors to stop over-prescribing antibiotics. If it were that simple….

When a patient comes in complaining of what a physician judge to be “a cold”, the physician may very well tell the patient, “Go home, sip lots of hot tea and chicken soup, get plenty of rest, and take some decongestant for the symptoms.”

Then that patient says, “But I waited in your damn office for 45 minutes! You’d better get me SOMETHING.”

In other words, the patient EXPECTS the doctor to write a prescription for what the patient perceives to be “more than just” a cold.

If that doctor tries to educate the patient on the broader consequences of antibiotic overuse, the patient may very well continue to demand (DEMAND!) that the doctor write a prescription for an antibiotic (yes, here in the U.S. many patients aren’t afraid to tell doctor what they want prescriptions for). If that doctor refuses, the patient simply goes to another doctor, who is willing to write the prescription.

So I don’t care if we come up with nth generation macrolide / cephalosporin or we engineer a quinolone that won’t cause such serious adverse events that half of the drugs in that class has been pulled off the shelf…

I don’t care if we start ‘designing’ antibiotics that overcome a microbe’s awesome drug-effluxing receptors…

it is only a matter of time that we create enough selective pressure for a bug to breed and mutate into a superbug that not only will clip whatever enzyme an antibiotic uses to disable the superbug’s replication system but will pump and dump that antibiotic faster than you can say “vancomycin”.

The most important thing we can do is to curb society’s demand for antibiotics for conditions that does not warrant antibiotics, and hope that pharmaceutical sciences can catch up with the superbugs.