User Tools

Site Tools


Tell your friends about

There are many reasons to “Vote with Your Feet” and move from corrupt, statist, liberal-Democrat, high-crime Nanny States to a low-population-density, extremely low-crime, limited government, libertarian, Constitution-loving, Pro-Second-Amendment, Patriotic, moral-conservative, God-fearing, safe-haven refuge in the American Redoubt of Idaho - Montana - Wyoming - Eastern Oregon - Eastern Washington - Northern Utah

Vote with your feet by moving ( to the libertarian safe refuge of the “American Redoubt” in Idaho - Montana - Wyoming - Eastern Oregon - Eastern Washington - Northern Utah or the Texas Redoubt or the Tennessee Cumberland Redoubt ( for more Bill of Rights freedom, especially Second Amendment gun rights — see

for state rankings,,, podcast, podcast by a conservative black Catholic Redoubter.

Sadly, the beautiful state of California is now a lost cause politically. But still keep fighting to restore her greatness.

NRA Life Member; also member of of America,, Second Amendment Foundation,,,,,,, Member Support Brigade, the Wolf Pack at, Permaculture Homesteader

American Redoubt Pages:

What exactly is the American Redoubt? See for more details from James Wesley Rawles, whose description of our Redoubt many of us wholeheartedly support.

We are “Prepared Individuals Living in Uncertain Times” is the motto of James Wesley Rawles

We Vote-with-our-Feet and have prepared “For when times get tough, or even if they don't” - the motto of Jack Spirko's SurvivalPodcast (

One could say that the American Redoubt was “founded” when Montana became a State of these United States of America on November 8, 1889, just 1 year before Idaho and Wyoming.

For those who are more attached to the East Coast and can't easily migrate to the American Redoubt in the Intermountain-West, we recommend the blog of the inspirational M.D. Creekmore who posted Joel M. Skousen, Author, Strategic Relocation North American Guide to Safe Places, on the Tennessee Cumberland Plateau solution to the “The East Coast Retreat Dilemma”:

“As a relocation specialist and designer, I found safe retreat locations and helped clients develop high security homes in every state of the union and you can too. The concept that anyone caught East of the Mississippi River is doomed is only partially valid and highly exaggerated. You can achieve a significantly higher level of safety going beyond the Appalachians to the high plateau regions of Tennessee and Kentucky. This massive and relatively unpopulated area is called the Cumberland Plateau—most of which falls within the state of Tennessee.” Joel M. Skousen ( is a relocation specialist and author of “Strategic Relocation North American Guide to Safe Places.”

Snippet from Wikipedia: Diphenhydramine

Diphenhydramine is an antihistamine mainly used to treat allergies. It is also used for insomnia, symptoms of the common cold, tremor in parkinsonism, and nausea. It is used by mouth, injection into a vein, and injection into a muscle. Maximal effect is typically around two hours after a dose, and effects can last for up to seven hours.

Common side effects include sleepiness, poor coordination, and an upset stomach. Its use is not recommended in young children or the elderly. There is no clear risk of harm when used during pregnancy; however, use during breastfeeding is not recommended. It is a first generation H1-antihistamine and works by blocking certain effects of histamine. Diphenhydramine is also an anticholinergic.

Diphenhydramine was first made by George Rieveschl and came into commercial use in 1946. It is available as a generic medication. The wholesale price in the developing world as of 2014 is about US$0.01 per dose. In the United States, it costs less than US$25 for a typical month’s supply. It is sold under the trade name Benadryl, among others. In 2016 it was the 210th most prescribed medication in the United States with more than 2 million prescriptions.

<!–Pharmacokinetic data–>


<!–Chemical data–>

C = 17 H = 21 N = 1


Diphenhydramine (

; abbreviated DPH, sometimes DHM) is a first-generation antihistamine possessing anticholinergic, antitussive, antiemetic, and sedative properties that is mainly used to treat allergies. It is also used in the management of drug-induced parkinsonism and other extrapyramidal symptoms. The drug has a strong hypnotic effect and is FDA-approved as a non-prescription sleep aid, especially in the form of diphenhydramine citrate. It is produced and marketed under the trade name Benadryl by McNeil-PPC (a division of Johnson & Johnson) in the U.S., Canada and South Africa (trade names in other countries include Dimedrol, Daedalon and Nytol). It is also available as a generic or store brand medication.

Medical uses

Diphenhydramine is a first-generation antihistamine used to treat a number of conditions including allergic symptoms and itchiness, the common cold, insomnia, motion sickness, and extrapyramidal symptoms.<ref name=“AHFS_monograph”>

</ref><ref name=“Brown_2012”>


Diphenhydramine is significantly more potent in treatment of allergies than a newer generation of antihistamines.<ref name=“pmid16680933”>

</ref> As a consequence, it is frequently used when an allergic reaction requires fast, effective reversal of a massive histamine release. Diphenhydramine is available as an over-the-counter drug (OTC) or prescription-only solution for injection. Injectable diphenhydramine can be used for life-threatening reactions (anaphylaxis) to allergens such as bee stings, peanuts, or latex, as an adjunct to epinephrine.<ref name=“Current EM”>


As a potent antagonist to acetylcholine in muscarinic receptors, diphenhydramine is used to treat Parkinson's disease-like extrapyramidal symptoms caused by antipsychotics. The muscarinic receptor antagonism leads to correction of levels of dopamine, the neurotransmitter responsible for control of motor function in the brain, similar to the effect of other antimuscarinic agents such as atropine.<ref name=“Katzung Basic Ch28”>

</ref> Diphenhydramine can cause strong sedation and has also been used as an anxiolytic as a result.<ref name=“Dinndroff_1998”>

</ref> It has also proven to have mild anti-obsessive effects in one study researching OCD medication. Originally intended to act as a control medication, it in fact produced a significant decrement in OCD symptoms.<ref>


<!– Deleted image removed:

–> Because of these sedative properties, diphenhydramine is widely used in nonprescription sleep aids for insomnia. The maximum recommended dose is 50&nbsp;mg (as the hydrochloride salt), as mandated by the U.S. FDA. The drug is an ingredient in several products sold as sleep aids, either alone or in combination with other ingredients such as acetaminophen (paracetamol). An example of the latter is Tylenol PM. Examples of products having diphenhydramine as the only active ingredient include Unisom, Tylenol Simply Sleep, Nytol, ZzzQuil, and Sominex (the version sold in the US and Canada; that sold in the UK uses promethazine). Tolerance against the sedating effect of diphenhydramine builds very quickly; after three days of use at the common dosage, it is no more effective than a placebo.<ref name=“pmid12352276”>

</ref> Diphenhydramine can cause minor psychological dependence when used improperly.<ref>


Diphenhydramine also has antiemetic properties, which make it useful in treating the nausea that occurs in motion sickness. As it causes marked sedation in many individuals, newer-generation antihistamines, including loratadine, cetirizine, and dimenhydrinate, may be preferred for antiemetic use.<ref name=“Katzung Basic Ch16”>


There are also topical formulations of diphenhydramine available, including creams, lotions, gels, and sprays. These are used to relieve itching, and have the advantage of causing much less systemic effect (i.e., drowsiness) than oral forms.<ref name = “MedlinePlus_Diphenhydramine”>

</ref> Diphenhydramine also has local anesthetic properties, and has been used as such in patients allergic to common local anesthetics like lidocaine.<ref name=“pmid10456039”>


Adverse effects

Diphenhydramine is a potent anticholinergic agent. This activity is responsible for the side-effects of dry mouth and throat, increased heart rate, pupil dilation, urinary retention, constipation, and, at high doses, hallucinations or delirium. Other side-effects include motor impairment (ataxia), flushed skin, blurred vision at nearpoint owing to lack of accommodation (cycloplegia), abnormal sensitivity to bright light (photophobia), sedation, difficulty concentrating, short-term memory loss, visual disturbances, irregular breathing, dizziness, irritability, itchy skin, confusion, increased body temperature (in general, in the hands and/or feet), temporary erectile dysfunction, excitability, and, although it can be used to treat nausea, higher doses may cause vomiting.<ref name=“diph effects”>

</ref> Some side-effects, such as twitching, may be delayed until the drowsiness begins to cease and the person is in more of an awakening mode.

Acute poisoning can be fatal, leading to cardiovascular collapse and death in 2–18 hours, and in general is treated using a symptomatic and supportive approach.<ref name=“Goodman”/> Diagnosis of toxicity is based on history and clinical presentation, and in general specific levels are not useful.<ref name=“Poisoning&Overdoses”>

</ref> There are several levels of evidence strongly indicating diphenhydramine (similar to chlorpheniramine) can block the delayed rectifier potassium channel and, as a consequence, prolong the QT interval, leading to cardiac arrhythmias such as torsades de pointes.

There is no specific antidote for diphenhydramine toxicity, but the anticholinergic syndrome has been treated with physostigmine for severe delirium or tachycardia.<ref name=“Poisoning&Overdoses”/> Benzodiazepines may be administered to decrease the likelihood of psychosis, agitation, and seizures in patients who are prone to these symptoms.<ref>


Some patients have an allergic reaction to diphenhydramine in the form of hives.<ref name=“pmid9007386”>

</ref><ref name=“pmid6219138”>

</ref> However, restlessness or akathisia can also be a side-effect made worse by increased levels of diphenhydramine, especially with recreational dosages.<ref name=“pmid18227744”>

</ref> As diphenhydramine is extensively metabolized by the liver, caution should be exercised when giving the drug to individuals with hepatic impairment.

Special populations

Diphenhydramine is not recommended for patients older than 60 or children under the age of six, unless a physician is consulted.<ref name=“Physicians Desk”>

</ref> These populations should be treated with second-generation antihistamines such as loratadine, desloratadine, fexofenadine, cetirizine, levocetirizine, and azelastine.<ref name=“Goodman” /> Due to its strong anticholinergic effects, diphenhydramine is on the “Beers list” of drugs to avoid in the elderly.<ref name=“”>


Diphenhydramine is Category B in the FDA Classification of Drug Safety During Pregnancy.<ref name=“Black”>

</ref> Diphenhydramine is also excreted in breast milk.<ref name=“pmid11456429”>

</ref> Paradoxical reactions to diphenhydramine have been documented, in particular among children, and it may cause excitation instead of sedation.<ref name=“pmid18227744”>


Topical diphenhydramine is sometimes used especially on patients in hospice. This use is without indication and topical diphenhydramine should not be used as treatment for nausea because research does not indicate that this therapy is more effective than alternatives.<ref name=“AAHPMfive”>

, which cites

  • </ref>

Measurement in body fluids

Diphenhydramine can be quantitated in blood, plasma, or serum.<ref name=“Analytical Separation Handbook”>

</ref> Gas chromatography with mass spectrometry (GC-MS) can be used with electron ionization on full scan mode as a screening test. GC-MS or GC-NDP can be used for quantification.<ref name=“Analytical Separation Handbook” /> Rapid urine drug screens using immunoassays based on the principle of competitive binding may show false-positive methadone results for patients having ingested diphenhydramine.<ref name=“pmid20838187”>

</ref> Quantitation can be to used monitor therapy, confirm a diagnosis of poisoning in hospitalized patients, provide evidence in an impaired driving arrest, or assist in a death investigation.<ref name=“Analytical Separation Handbook”/>

Mechanism of action

Overview of diphenhydramine targets and effects
Biological target Mode of action Effect
H<sub>1</sub> receptor <br> (Peripheral) Inverse agonist Allergy relief
H1 receptor <br> (Central) Antagonist Sedation
M Receptors Antagonist Anticholinergic<br/> Antiparkinson
Na channel Blocker Local anesthetic
SERT Inhibitor Mood alteration

Diphenhydramine is an inverse agonist of the histamine H<sub>1</sub> receptor.<ref name=“pmid11428864”>

</ref> It is a member of the ethanolamine class of antihistaminergic agents.<ref name=“Goodman”>

</ref> By reversing the effects of histamine on the capillaries, it can reduce the intensity of allergic symptoms. Diphenhydramine also crosses the blood–brain barrier and antagonizes the H1 receptors centrally. Its effects on central H1 receptors cause drowsiness.<ref>


Like many other first-generation antihistamines, diphenhydramine is also a potent antimuscarinic (a competitive antagonist of muscarinic acetylcholine receptors) and, as such, at high doses can cause anticholinergic syndrome.<ref name=“urlAntihistamine Toxicity”>

</ref> The utility of diphenhydramine as an antiparkinson agent is the result of its blocking properties on the muscarinic acetylcholine receptors in the brain.

Diphenhydramine also acts as an intracellular sodium channel blocker, which is responsible for its actions as a local anesthetic.<ref name=“pmid11036158”>

</ref> Diphenhydramine has also been shown to inhibit the reuptake of serotonin.<ref name=“Domino_1999”/>

Diphenhydramine has been shown to be a potentiator of analgesia induced by morphine in rats.<ref name=“pmid2860599”>

</ref> Opioid users, report that Diphenhydramine potentiates any opioid drug, and not just Morphine. The mechanism behind this action is poorly understood. However, many hypotheses exist. Diphenhydramine could potentially have interaction with either the Kappa (κ), Delta (δ) or Mu (μ) opiate receptors. This is highly unlikely, but a possibility none-the-less. More likely hypotheses are based around diphenhydramine's antimuscarinic action, and its possible indirect antiglutaminergic and antiadrenergic effects.


Oral bioavailability of diphenhydramine is in the range of 40–60% and peak plasma concentration occurs approximately 2–3 hours after administration.<ref name=“pmid2866055”/> The primary route of metabolism is two successive demethylations of the tertiary amine. The resulting primary amine is further oxidized to the carboxylic acid.<ref name=“pmid2866055”/> The half-life is as short as 8 hours in children to 17 hours in the elderly.<ref name=“pmid2391399”/>

Recreational use

Diphenhydramine is sometimes used as a recreational drug, often by those without access to illegal drugs.<ref name=“urlAtypical Drugs of Abuse”>

</ref> These people use it for the sedative properties, as well as the delirium-induced hallucinations at higher doses. Diphenhydramine abuse may cause:

  • Euphoria
  • Dysphoria
  • Hallucinations (Auditory, Visual, etc.)
  • Heart palpitations
  • Extreme drowsiness
  • Severe dizziness
  • Abnormal speech (inaudibility, forced speech, etc.)
  • Flushed Skin
  • Severe mouth and throat dryness
  • Tremors
  • Seizures
  • Inability to urinate
  • Vomiting
  • Motor disturbances
  • Anxiety/nervousness
  • Disorientation
  • Stomach pain
  • Delirium
  • Coma
  • Death.<ref name=“urlDiphenhydramine overdose: MedlinePlus Medical Encyclopedia”>



Diphenhydramine was discovered in 1943 by George Rieveschl, a former professor at the University of Cincinnati.<ref>

</ref> In 1946, it became the first prescription antihistamine approved by the U.S. Food and Drug Administration (FDA).<ref name=“BC”>

</ref> Diphenhydramine can be synthesized by a simple reaction of Bromodiphenylmethane and 2-dimethylaminoethanol.<ref name = “US2397799”>

</ref><ref name = “US2421714”>

</ref><ref name = “US2427878”>


In the 1960s, diphenhydramine was found to inhibit reuptake of the neurotransmitter serotonin.<ref name=“Domino_1999”/> This discovery led to a search for viable antidepressants with similar structures and fewer side-effects, culminating in the invention of fluoxetine (Prozac), a selective serotonin reuptake inhibitor (SSRI).<ref name=“Domino_1999”>

</ref><ref name=“url_Adawi_Awdish”>

</ref> A similar search had previously led to the synthesis of the first SSRI, zimelidine, from brompheniramine, also an antihistamine.<ref name=“Barondes”>


Society and culture

Diphenhydramine is sometimes used recreationally as a deliriant, or as a potentiator of alcohol,<ref name=“urlDiphenhydramine and Alcohol / Food Interactions -”>

</ref><ref name=“pmid10344773”>

</ref> opiates,<ref name=“urlOpiate potentiation and side-effects”>

</ref> DXM and other depressants. Diphenhydramine is deemed to have limited abuse potential in the United States due its potentially serious side-effect profile and limited euphoric effects, and is not a controlled substance. Since 2002, the U.S. FDA has required special labeling warning against use of multiple products that contain diphenhydramine.<ref>

</ref> In some jurisdictions, diphenhydramine is often present in postmortem specimens collected during investigation of sudden infant deaths; the drug may play a role in these events.<ref name=“pmid16419411”>

</ref><ref name=“isbn0-9626523-7-7”>


Diphenhydramine is among the prohibited and controlled substances in the Republic of Zambia.<ref>

</ref> Travelers are advised not to bring this drug into the country. Several Americans have been detained by the Zambian Drug Enforcement Commission for possession of Benadryl and other over-the-counter medications containing diphenhydramine.<ref>


See also


Further reading

diphenhydramine.txt · Last modified: 2017/03/30 12:06 (external edit)