Hyoscyamine And Phenyltoloxamine
Hyoscyamine And Phenyltoloxamine Uses, Dosage, Side Effects, Food Interaction and all others data.
Hyoscyamine is a tropane alkaloid and the levo-isomer of atropine. It is commonly extracted from plants in the Solanaceae or nightshade family. Research into the action of hyoscyamine in published literature dates back to 1826. Hyoscyamine is used for a wide variety of treatments and therapeutics due to its antimuscarinic properties.
Although hyoscyamine is marketed in the United States, it is not FDA approved.
Hyoscyamine is not FDA approved, and so it has not official indications. However, it is used as an antimuscarinic agent in a number of treatments and therapies. Hyoscyamine has a short duration of action as it may need to be given multiple times per day. Patients should be counselled regarding the risks and signs of anticholinergic toxicity.
Phenyltoloxamine is an antihistamine drug with sedative and analgesic effects. It is a H1 receptor blocker and a member of the ethanolamine class of antihistaminergic drugs. It is available in combination products that also contain other analgesics and antitussives such as acetaminophen. Phenyltoloxamine citrate is the more common salt form that acts as an active ingredient in pharmaceutical products and promotes hay fever relief via reversing the effects of histamine. Phenyltoloxamine acts as an adjuvant analgesic, which augments the analgesic effect of acetaminophen. It also potentiates the effects of other drugs, such as codeine and codeine derivatives.
Although phenyltoloxamine's ability to potentiate the effects of analgesics may be explained in part by its chemical nature as a first-generation H1 antihistamine that is capable of crossing the blood-brain barrier and causing tranquilizing effects at CNS histamine receptors, many of the drug's specific pharmacokinetics are not readily available - perhaps also because many early (phenyltoloxamine was involved in studies as early as the 1950s) first-generation antihistamines were not optimally investigated . Nevertheless, phenyltoloxamine is used to a fairly limited extent in contemporary medicine, with only very few products involving it as an active ingredient.
As a member of the first generation H1 antihistamines, it is known that phenyltoloxamine - like virtually all first generation H1 antihistamines - has a propensity for crossing the blood-brain barrier and acting on H1 histamine receptors there to interfere with neurotransmission . The most common results of this kind of first generation H1 antihistamine CNS neurotransmission interference are adverse effects like drowsiness, sedation, somnolence, and fatigue . Given these effects, under specific circumstances like a patient experiencing a pain or a cough that may be preoccupying all of their waking energy and attention, it is perhaps possible that the sedative and tranquilizing characteristics of phenyltoloxamine may be the factors that contribute to its apparent adjunctive analgesic and antitussive actions .
| Trade Name | Hyoscyamine And Phenyltoloxamine |
| Generic | Hyoscyamine + phenyltoloxamine |
| Weight | 0.0625mg + 15mg |
| Type | Oral capsule |
| Therapeutic Class | |
| Manufacturer | |
| Available Country | United States |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Hyoscyamine is an anticholinergic indicated to treat functional gastrointestinal disorders, biliary and renal colic, and acute rhinitis.
As a drug that is not FDA approved, hyscyamine has no official indications. Intravenous hysocyamine has been used to reduce gastric motility, reduce pancreatic pain and secretions, to facilitate imaging of the gastrointestinal tract, treat anticholinesterase toxicity, treat certain cases of partial heart block, improve visualization of the kidneys, and for symptomatic relief of biliary and renal colic. Intravenous hyoscyamine is also used pre-operatively to reduce secretions of the mouth and respiratory tract to facilitate intubation. Oral hyoscyamine is used to treat functional intestinal disorders, for symptomatic relief of biliary and renal colic, and symptomatic relief of acute rhinitis.
Phenyltoloxamine is a medication used to treat minor aches and pains.
The primary therapeutic use for which phenyltoloxamine is currently indicated is as an adjuvant therapy in various combination products containing an analgesic(s) (either narcotic or non-narcotic), where it is expected to potentiate the pain relieving, anti-tussive, etc. effect(s) of the analgesic component of the product.
In that regard, some of these aforementioned combination products are typically indicated for the temporary relief of minor aches and pains like headache, muscular aches, backaches, minor arthritis pain, common cold, toothaches, menstrual cramps, etc ; or perhaps for the treatment of exhausting or non-productive cough, associated with cold or with upper respiratory allergic condition that does not respond to non-narcotic antitussives .
Hyoscyamine And Phenyltoloxamine is also used to associated treatment for these conditions: Biliary Colic, Colic, Cystitis, Diverticulitis, Heart Block, Irritable Bowel Syndrome (IBS), Neurogenic Bladder Dysfunction, Neurogenic Bowel Dysfunction, Pancreatitis, Parkinsonism, Peptic Ulcer, Poisoning caused by anticholinesterases, Pylorospasm, Renal Colic, Spastic bladder, Tracheo-bronchial secretion excess, Acute Enterocolitis, Acute Rhinitis, Gastric secretions, Mild Dysentery, Pharyngeal secretions, Salivary secretions, Spastic colitisBronchitis, Cough, Minor aches and pains, Airway secretion clearance therapy
How Hyoscyamine And Phenyltoloxamine works
Hyoscyamine competitively and non-selectively antagonises muscarinic receptors in the smooth muscle, cardiac muscle, sino-atrial node, atrioventricular node, exocrine nodes, gastrointestinal tract, and respiratory tract. Antagonism of muscarinic M1, M4, and M5 receptors in the central nervous system lead to cognitive impairment; antagonism of M2 in the sinoatrial and atrioventricular nodes leads to bradycardia and lowers contractility; and antagonism of M3 in smooth muscle results in reduced peristalsis, bladder contraction, salivary secretions, gastric secretions, bronchial secretions, sweating, increased bronchodilation, mydriasis, and cycloplegia.
As a first-generation H1 antihistamine, phenyltoloxamine interferes with the agonist activity of histamine at the H1 receptor and are ostensibly used to attenuate inflammatory processes as a means to treat conditions like allergic rhinitis, allergic conjunctivitis, and urticaria . Reduction of the activity of the NF-kB (nuclear factor kappa-light-chain-enhancer of activated B cells) immune response transcription factor via the phospholipase C and phosphatidylinositol (PIP2) signaling pathways also serves to decrease antigen presentation and the expression of pro-inflammatory cytokines, cell adhesion molecules, and chemotactic factors . Moreover, lowering calcium ion concentration leads to increased mast cell stability which reduces further histamine release .
Additionally, first-generation antihistamines like phenyltoloxamine readily cross the blood-brain barrier and cause sedation and other adverse central nervous system (CNS) effects, like nervousness and insomnia . By comparison, second-generation antihistamines are more selective for H1 receptors in the peripheral nervous system and do not cross the blood-brain barrier, resulting in fewer adverse drug effects overall .
Furthermore, although some studies propose that phenyltoloxamine may possess some intrinsic antispasmodic and distinct local anesthetic properties , the specific mechanisms of action for these effects have not been formalized. Also, even though the combination of phenyltoloxamine's ability to cross the blood-brain barrier and cause various tranquilizing effects may explain to some extent how it may be able to potentiate analgesic effects , there are also studies that observed no potentiating effects associated with phenyltoloxamine use either .
Toxicity
Patients experiencing an overdose may present with headache, nausea, vomiting, dizziness, dry mouth, difficulty in swallowing, dilated pupils, blurred vision, urinary retention, hot dry and flushed skin, tachycardia, hypertension, hypotension, respiratory depression, CNS stimulation, fever, ataxia, excitation, lethargy, stupor, coma, and paralysis. Patients should be treated with symptomatic and supportive therapy which may include emesis, gastric lavage, activated charcoal, artificial respiration, or intravenous physostigmine. Dialysis is expected to remove hyoscyamine sulfate from circulation.
Toxicity after overdose may involve CNS effects like extreme drowsiness, lethargy, confusion, delirium, and coma in adults; paradoxical excitation, irritability, hyperactivity, insomnia, hallucinations, seizures, and respiratory depression or arrest in infants and young children, CNS adverse effects predominate o er cardiac adverse effects; death may occur within hours after ingestion of drug in untreated patients; rhabdomyolysis has also been reported .
Volume of Distribution
Readily accessible data regarding the volume of distribution of phenyltoloxamine is not available. In fact, many first-generation H1 antihistamines have never had their pharmacokinetics (ie. absorption, distribution, metabolism, and elimination) optimally investigated .
Elimination Route
Hyoscyamine is completely absorbed by sublingual and oral routes, though exact data regarding the Cmax, Tmax, and AUC are not readily available.
Readily accessible data regarding the absorption of phenyltoloxamine is not available. In fact, many first-generation H1 antihistamines have never had their pharmacokinetics (ie. absorption, distribution, metabolism, and elimination) optimally investigated .
Half Life
The half life of hyoscyamine is 3.5 hours.
Readily accessible data regarding the half-life of phenyltoloxamine is not available. In fact, many first-generation H1 antihistamines have never had their pharmacokinetics (ie. absorption, distribution, metabolism, and elimination) optimally investigated .
Clearance
Readily accessible data regarding the clearance of phenyltoloxamine is not available. In fact, many first-generation H1 antihistamines have never had their pharmacokinetics (ie. absorption, distribution, metabolism, and elimination) optimally investigated .
Elimination Route
The majority of hyoscyamine is eliminated in the urine as the unmetabolized parent compound.
Readily accessible data regarding the primary route of elimination of phenyltoloxamine is not available. In fact, many first-generation H1 antihistamines have never had their pharmacokinetics (ie. absorption, distribution, metabolism, and elimination) optimally investigated .
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