RAW 264.7 macrophages' LPS-induced cytokine secretion (IL-1β, IL-6, and TNFα) and cell proliferation rate are inhibited by vannicline diHClide (1 μM, 24 h) [1]. Human adrenal chromaffin cells separated from male and female organ donors exhibit action potentials (Aps) stimulation in the absence of ACh stimulation when exposed to 250 nM vannicline diHClide [3]. By lowering VE-cadherin protein expression, vannicline diHClide (100 μM, 4 h) stimulates HUVEC migration [4].

Nicotine conditioned place preference (CPP) is inhibited by vannicline disalk (0.01-1 mg/kg subcutaneously, 3 days), when administered 10 minutes prior to nicotine (0.5 mg/kg subcutaneously) [5]. Position aversion caused by vannicline diHClide (subcutaneous injection, 2.5 mg/kg, 3 days) is dependent on α5 nAChR but not β2 nAChR [5]. Subcutaneous injection of vannicline diHClide (0.1 and 0.5 mg/kg, 3 days) reverses the somatic symptoms and hyperalgesia associated with nicotine withdrawal, as well as withdrawal-induced aversion, in a dose-related manner [5].

Cell proliferation assay [1]
Cell Types: RAW 264.7 mouse macrophages (treated with 4 μg/mL LPS for 24 h)
Tested Concentrations: 1 μM
Incubation Duration: 0-48 h
Experimental Results: LPS-induced cell proliferation rate diminished.

---

Western Blot Analysis[4]
Cell Types: HUVEC
Tested Concentrations: 1, 10, 100 μM
Incubation Duration: 24 hrs (hours) or 30 minutes
Experimental Results: diminished VE-cadherin protein expression, activation of ERK1/2, p38 and JNK signaling.

Animal/Disease Models: ICR male mice [5]
Doses: 0.01-1 mg/kg, 3 days
Route of Administration: subcutaneous injection
Experimental Results: Inhibited nicotine conditioned place preference (CPP) in a dose-dependent manner.

Absorption, Distribution and Excretion
Varenicline undergoes minimal metabolism, with 92% excreted unchanged in the urine. Renal elimination of varenicline is primarily through glomerular filtration along with active tubular secretion possibly via the organic cation transporter, OCT2.
Maximum plasma concentrations of varenicline occur typically within 3-4 hours after oral administration. Following administration of multiple oral doses of varenicline, steady-state conditions were reached within 4 days. Over the recommended dosing range, varenicline exhibits linear pharmacokinetics after single or repeated doses. In a mass balance study, absorption of varenicline was virtually complete after oral administration and systemic availability was ~90%. Oral bioavailability of varenicline is unaffected by food or time-of-day dosing. Plasma protein binding of varenicline is low (Varenicline is eliminated principally in urine as unchanged drug. Renal elimination of the drug occurs primarily through glomerular filtration along with active tubular secretion.
Varenicline is distributed into milk in animals. Not known whether varenicline is distributed into human milk.

---

Metabolism / Metabolites
Metabolism is limited (<10%). Most of the active compound is excreted by the kidneys (81%). A minor amount of varenicline is glucuronidated, oxidated, N-formylated, as well as conjugated to form a hexose.
Varenicline undergoes minimal metabolism, with 92% excreted unchanged in the urine.
Varenicline undergoes minimal metabolism with 92% excreted unchanged in the urine and less than 10% excreted as metabolites. Minor metabolites in urine include varenicline N-carbamoylglucuronide and hydroxyvarenicline. In circulation, varenicline comprises 91% of drug related material. Minor circulating metabolites include varenicline N-carbamoylglucuronide and N-glucosylvarenicline.

---

Biological Half-Life
The elimination half-life of varenicline is approximately 24 hours
The elimination half-life of varenicline is approximately 24 hours.

Hepatotoxicity
Varenicline has not been associated with rates of serum enzyme elevations during therapy greater than occurs with placebo therapy, but information on these abnormalities is limited and occasional instances of asymptomatic ALT elevations leading to drug discontinuation have been reported. In prelicensure pivotal registration trials in several thousand patients, varenicline was not associated with cases of jaundice or hepatitis. Since licensure, rare case reports of serum enzyme elevations without jaundice arising within 4 weeks of starting varenicline have been published, but largely in patients with other causes of liver injury (alcoholic liver disease, hepatitis C). The injury was self-limited in course and not associated with immunoallergic or autoimmune features. In Iceland, a single case of varenicline hepatotoxicity has been reported (Case 1), there having been an estimated 20,000 persons treated with the drug in the country since its introduction.
Likelihood score: C (probable rare cause of clinically apparent liver injury).

---

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Varenicline is a partial nicotine agonist used orally to assist smoking cessation and by nasal spray for dry eyes. One researcher points out that based on animal data on nicotine, varenicline might interfere with normal infant lung development and recommends against its use in nursing mothers. Because no information is available on the use of varenicline during breastfeeding, an alternate drug is preferred, especially while nursing a newborn or preterm infant. However, maternal drug exposure after the nasal spray is only about 7.5% that of the oral drug, so the spray is much less likely to affect the infant. If a mother chooses to breastfeed while taking varenicline, she should monitor her infant for seizures and excessive vomiting.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

---

Protein Binding
Less than 20%.

[1]. Elif Baris, et al. Varenicline Prevents LPS-Induced Inflammatory Response via Nicotinic Acetylcholine Receptors in RAW 264.7 Macrophages. Front Mol Biosci. 2021 Oct 12;8:721533.
[2]. Mihalak KB, et al. Varenicline is a partial agonist at alpha4beta2 and a full agonist at alpha7 neuronal nicotinic receptors.Mol Pharmacol. 2006 Sep;70(3):801-5. Epub 2006 Jun 9.
[3]. Jin H, et al. Therapeutic concentrations of varenicline in the presence of nicotine increase action potential firing in human adrenal chromaffin cells. J Neurochem. 2017 Jan;140(1):37-52.
[4]. Mitsuhisa Koga, et al. Varenicline promotes endothelial cell migration by lowering vascular endothelial-cadherin levels via the activated α7 nicotinic acetylcholine receptor-mitogen activated protein kinase axis. Toxicology. 2017 Sep 1;390:1-9.
[5]. Bagdas D, et al. New insights on the effects of varenicline on nicotine reward, withdrawal and hyperalgesia in mice.Neuropharmacology. 2018 Aug;138:72-79.

Varenicline is a prescription medication used to treat smoking addiction. This medication is the first approved nicotinic receptor partial agonist. Specifically, varenicline is a partial agonist of the alpha4/beta2 subtype of the nicotinic acetylcholine receptor. In addition it acts on alpha3/beta4 and weakly on alpha3beta2 and alpha6-containing receptors. A full agonism was displayed on alpha7-receptors. On March 9, 2015, the U.S. Food and Drug Administration warned that Varenicline, in the form of Pfizer Inc's quit-smoking drug, Chantix, has been associated with seizures and that some patients who drink while taking the drug may become aggressive or black out. Pfizer is conducting an additional safety study of the drug, results of which are expected in late 2015. The FDA said it is keeping the black box in place at least until the results of the trial are announced.
Varenicline is a partial agonist of the nicotinic acetylcholine receptor and is used to help in smoking cessation. Varenicline has been associated with a low rate of serum enzyme elevations during therapy and, since approval and its widescale use, with rare instances of clinically apparent mild liver injury.
Varenicline is a partial agonist of the nicotinic acetylcholine receptor (nAChR) subtype alpha4beta2. Nicotine stimulation of central alpha4beta2 nAChRs located at presynaptic terminals in the nucleus accumbens causes the release of the neurotransmitter dopamine, which may be associated with the experience of pleasure; nicotine addiction constitutes a physiologic dependence related to this dopaminergic reward system. As an AChR partial agonist, varenicline attenuates the craving and withdrawal symptoms that occur with abstinence from nicotine but is not habit-forming itself.
A benzazepine derivative that functions as an ALPHA4-BETA2 NICOTINIC RECEPTOR partial agonist. It is used for SMOKING CESSATION.
See also: Varenicline dihydrochloride (annotation moved to).

---

Drug Indication
For use as an aid in smoking cessation. Varenicline as a nasal spray is indicated for the symptomatic treatment of dry eye disease.
FDA Label

---

Mechanism of Action
Varenicline is an alpha-4 beta-2 neuronal nicotinic acetylcholine receptor partial agonist. The drug shows high selectivity for this receptor subclass, relative to other nicotinic receptors (>500-fold alpha-3 beta-4, >3500-fold alpha-7, >20,000-fold alpha-1 beta gamma delta) or non-nicotinic receptors and transporters (>2000-fold). The drug competitively inhibits the ability of nicotine to bind to and activate the alpha-4 beta-2 receptor. The drug exerts mild agonistic activity at this site, though at a level much lower than nicotine; it is presumed that this activation eases withdrawal symptoms.
Varenicline is a selective alpha4beta2 nicotinic acetylcholine receptor partial agonist. The drug binds with high affinity and selectivity to alpha4beta2 nicotinic acetylcholine receptors located in the brain and stimulates receptor-mediated activity, but at a substantially lower level than nicotine;1 6 this low-level receptor stimulation and subsequent moderate, sustained release of mesolimbic dopamine are thought to reduce craving and withdrawal symptoms associated with smoking cessation. Varenicline also blocks the ability of nicotine to activate alpha4beta2 receptors, preventing nicotine-induced stimulation of the mesolimbic dopaminergic system and thereby reducing the reinforcement and reward effects of cigarette smoking.
... The rationale for and the design of alpha(4)beta(2) neuronal nicotinic acetylcholine receptor (nAChR) partial agonists as novel treatments for tobacco addiction. Such agents are expected to exhibit a dual action by sufficiently stimulating alpha(4)beta(2)-nAChR-mediated dopamine release to reduce craving when quitting and by inhibiting nicotine reinforcement when smoking. Potent and selective alpha(4)beta(2) nAChR partial agonists that exhibit dual agonist and antagonist activity in preclinical models can be identified. The validity of this approach is demonstrated by the clinical efficacy of the alpha(4)beta(2) nAChR partial agonist varenicline, which has significantly better quit rates than do other treatments and offers a new option for smoking cessation pharmacotherapy.
... Varenicline has been shown to be a partial agonist of alpha4beta2 receptors, and in equilibrium binding assays, it is highly selective for the alpha4beta2 receptor. ... The functional activity of varenicline at a variety of rat neuronal nicotinic receptors expressed in Xenopus laevis oocytes and assayed under two-electrode voltage clamp /was examined/ . Varenicline is a potent, partial agonist at alpha4beta2 receptors, with an EC50 of 2.3 +/- 0.3 microM and an efficacy (relative to acetylcholine) of 13.4 +/- 0.4%. Varenicline has lower potency and higher efficacy at alpha3beta4 receptors, with an EC50 of 55 +/- 8 microM and an efficacy of 75 +/- 6%. Varenicline also seems to be a weak partial agonist at alpha3beta2 and alpha6-containing receptors, with an efficacy <10%. It is remarkable that varenicline is a potent, full agonist at alpha7 receptors with an EC50 of 18 +/- 6 microM and an efficacy of 93 +/- 7% (relative to acetylcholine). Thus, whereas varenicline is a partial agonist at some heteromeric neuronal nicotinic receptors, it is a full agonist at the homomeric alpha7 receptor. Some combination of these actions may be involved in the mechanism of varenicline as a smoking cessation aid.

C13H15CL2N3

284.1843

247.088

C, 54.94; H, 5.32; Cl, 24.95; N, 14.79

866823-63-4

Varenicline;249296-44-4;Varenicline-d4 hydrochloride;Varenicline-d4 dihydrochloride

45263226

Brown to dark brown solid powder

2.934

3

3

0

18

254

0

Cl.N1C2C(=CC3C4CC(CNC4)C=3C=2)N=CC=1

Varenicline dihydrochloride; HSDB7591; HSDB-7591; HSDB 7591; CP 526555; CP-526555; CP526555;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~62.5 mg/mL (~219.93 mM)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

---

Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

View More

Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

---

Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

View More

Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

---

Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

---

 (Please use freshly prepared in vivo formulations for optimal results.)