Tussionex
Tussionex Uses, Dosage, Side Effects, Food Interaction and all others data.
Hydrocodone is a synthetic opioid derivative of codeine. It is commonly used in combination with acetaminophen to control moderate to severe pain. Historically, hydrocodone has been used as a cough suppressant although this has largely been replaced by dextromethorphan in current cough and cold formulations. Hydrocodone's more potent metabolite, hydromorphone has also found wide use as an analgesic and is frequently used in cases of severe pain. The FDA first approved Hydrocodone for use as part of the cough suppressant syrup Hycodan in March of 1943.
Hydrocodone inhibits pain signaling in both the spinal cord and brain . Its actions in the brain also produce euphoria, respiratory depression, and sedation.
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 | Tussionex |
| Generic | phenyltoloxamine + hydrocodone |
| Type | Suspension, extended release |
| Therapeutic Class | |
| Manufacturer | |
| Available Country | Canada, United States, |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Hydrocodone is an opioid agonist used as an analgesic and antitussive agent.
Hydrocodone is indicated for the management of acute pain, sometimes in combination with acetaminophen or ibuprofen, as well as the symptomatic treatment of the common cold and allergic rhinitis in combination with decongestants, antihistamines, and expectorants.
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 .
Tussionex is also used to associated treatment for these conditions: Cough, Cough caused by Allergic Rhinitis, Cough caused by Common Cold, Nasal Congestion caused by Allergic Rhinitis, Nasal Congestion caused by Common Cold, Pain, Acute, Pain, Chronic, Rhinitis caused by Common Cold, Severe Pain, Moderate Pain, Upper respiratory symptoms caused by Allergic Rhinitis, Upper respiratory symptoms caused by Common ColdBronchitis, Cough, Minor aches and pains, Airway secretion clearance therapy
How Tussionex works
Hydrocodone binds to the mu opioid receptor (MOR) with the highest affinity followed by the delta opioid receptors (DOR). Hydrocodone's agonist effect at the MOR is considered to contribute the most to its analgesic effects. Both MOR and DOR are Gi/o coupled and and produces its signal through activation of inward rectifier potassium (GIRK) channels, inhibition of voltage gated calcium channel opening, and decreased adenylyl cyclase activity. In the dorsal horn of the spinal cord, activation of pre-synaptic MOR on primary afferents the inhibition of calcium channel opening and increased activity of GIRK channels hyperpolarizes the neuron and prevents release of neurotransmitters. Post-synaptic MOR can also prevent activation of neurons by glutamate through the aforementioned mechanisms.
Hydrocodone can also produce several actions in the brain similarly to other opioids. Activation of MOR in the periaquaductal gray (PAG) inhibits the GABAergic tone on medulo-spinal neurons. This allows these neurons, which project to the dorsal horn of the spinal cord, to suppress pain signalling in secondary afferents by activating inhibitory interneurons. MOR can also inhibit GABAergic neurons in the ventral tegmental area, removing the inhibitory tone on dopaminergic neurons in the nucleus accumbens and contributing to the activation of the brain's reward and addiction pathway. The inhibitory action or MOR likely contributes to respiratory depression, sedation, and suppression of the cough reflex.
Activation of DOR may contribute to analgesia through the above mechanisms but has not been well studied.
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
Overdosage with hydrocodone presents as opioid intoxication including respiratory depression, somnolence, coma, skeletal muscle flaccidity, cold and clammy skin, constricted pupils, pulmonary edema, bradycardia, hypotension, partial or complete airway obstruction, atypical snoring, and death.
In case of oversdosage the foremost priority is the maintenance of a patent and protected airway with the provision of assisted ventilation if necessary. Supportive measures such as IV fluids, supplemental oxygen, and vasopressors may be used to manage circulatory shock. Advanced life support may be necessary in the case of cardiac arrest or arrhythmias. Opioid antagonists such as naloxone may be used to reverse the respiratory and circulatory effects of hydrocodone. Emergency monitoring is still required after naloxone administration as the opioid effects may reappear. Additionally, if used in an opioid tolerant patient, naloxone may produce opioid withdrawal symptoms.
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
The apparent volume of distribution ranges widely in published literature. The official FDA labeling reports a value of 402 L. Pharmacokinetic studies report values from 210-714 L with higher values associated with higher doses or single dose studies and lower values associated with lower doses and multiple dose studies. Hydrocodone has been observed in human breast milk at levels equivalent to 1.6% of the maternal dosage. Only 12 of the 30 women studied had detectable concentrations of hydromorphone at mean levels of 0.3 mcg/kg/day.
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
The absolute bioavailability of hydrocodone has not been characterized due to lack of an IV formulation. The liquid formulations of hydrocodone have a Tmax of 0.83-1.33 h. The extended release tablet formulations have a Tmax of 14-16 h. The Cmax remains dose proportional over the range of 2.5-10 mg in liquid formulations and 20-120 mg in extended release formulations. Administration with food increases Cmax by about 27% while Tmax and AUC remain the same. Administration with 40% ethanol has been observed to increase Cmax 2-fold with an approximate 20% increase in AUC with no change in Tmax. 20% alcohol produces no significant effect.
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 elimination reported for hydrocodone is 7-9 h.
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
Official FDA labeling reports an apparent clearance of 83 L/h. Pharmacokinetic studies report values ranging from 24.5-58.8 L/h largely dependent on CYP2D6 metabolizer status.
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
Most hydrocodone appears to be eliminated via a non-renal route as renal clearance is substantially lower than total apparent clearance. Hepatic metabolism may account for a portion of this, however the slight increase in serum concentration and AUC seen in hepatic impairment indicates a different primary route of elimination.
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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