The Navigation Model of Therapy: Why Awareness Changes Everything
November 16, 2025
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Brand Name :
Verzenio
(United States) [Available]Synonyms :
Abemaciclib
Class :
Antineoplastics and CDK Inhibitors
Brand Name :
Verzenio
(United States) [Available]Synonyms :
Abemaciclib
Class :
Antineoplastics and CDK Inhibitors
Dosage Forms & Strengths  Â
Tablet  Â
50mg  Â
100mg  Â
150mg  Â
200mg  
150
mg
Orally
twice a day
; when used with tamoxifen or an aromatase inhibitor
The treatment needs to be continued for two years until the disease progression or unacceptable toxicity occurs
Monotherapy :
200
mg
Orally
twice a day
The treatment needs to be continued for two years until the disease progression or unacceptable toxicity occurs
When used in combination therapy with an aromatase inhibitor
150 mg orally taken twice a day PLUS an aromatase inhibitor
The treatment needs to be continued for two years until the disease progression or unacceptable toxicity occurs
Note:
This combination is helpful for initial endocrine-based therapy for postmenopausal women and men with HR-positive, HER2-negative advanced or metastatic breast cancer
When used in combination therapy with fulvestrant
150 mg orally taken twice a day PLUS Fulvestrant 500 mg given IM as on days 1, 15, and 29, and continue this course once monthly after that
The treatment needs to be continued for two years until the disease progression or unacceptable toxicity occurs
Note:
This combination is helpful with fulvestrant for adults with HR-positive, HER2-negative advanced or metastatic breast cancer with disease progression following endocrine therapy
may increase the serum concentration of abemaciclib
may increase the serum concentration of abemaciclib
may increase the serum concentration of abemaciclib
may increase the serum concentration of abemaciclib
may increase the serum concentration of abemaciclib
may increase the serum concentration of abemaciclib
may increase the serum concentration of abemaciclib
may enhance the metabolism of clobetasol propionate
when both drugs are combined, there may be increase in the serum concentration of abemaciclib 
when both drugs are combined, there may be increase in the serum concentration of abemaciclib 
may enhance the serum concentration of CYP3A4 inhibitors
may enhance the serum concentration of CYP3A4 Inhibitors
when both drugs are combined, there may be a reduced blood level of abemaciclib and result in less effectiveness in treating cancer  
when both drugs are combined, there may be an increased risk or severity of adverse effects  
when both drugs are combined, there may be an increased risk of developing an infection from the vaccine  
when both drugs are combined, there may be an increased risk or severity of adverse effects  
when both drugs are combined, there may be an increased effect of abemaciclib by affecting hepatic or intestinal enzyme CYP3A4 metabolism  
when both drugs are combined, there may be a reduced effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be a reduced effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be a reduced metabolism of abemaciclib    
when both drugs are combined, there may be a reduced metabolism of abemaciclib  
when both drugs are combined, there may be a reduced effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be a reduced effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be a reduced effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be a reduced effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be an increased risk or severity of adverse effects  
when both drugs are combined, there may be a reduced effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be a reduced effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism
may reduce the level of serum concentration of abemaciclib
may reduce the level of serum concentration of abemaciclib
may reduce the level of serum concentration of abemaciclib
may reduce the level of serum concentration of abemaciclib
may reduce the level of serum concentration of abemaciclib
may diminish the serum concentration of CYP3A4 inducers
may diminish the serum concentration of CYP3A4 inducers
It may diminish the effect when combined with phenobarbital by affecting the intestinal/hepatic enzyme CYP3A4
It may enhance the effect when combined with lonafarnib by affecting CYP3A4 metabolism
It may enhance the effect when combined with grapefruit by CYP3A4 metabolism
may diminish the concentration of serum when combined with abemaciclib
It may diminish the level when combined with efavirenz by affecting CYP3A4 metabolism
When nafcillin combines with abemaciclib, nafcillin will decrease the effect of action of abemaciclib by affecting enzyme CYP3A4 metabolism.
the effect of abemaciclib is increased by lorlatinib, by altering intestinal or hepatic CYP3A4 enzyme metabolism
when both drugs are combined, there may be a decreased effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
CYP3A strong enhancers of the small intestine may reduce the the bioavailability of abemaciclib
CYP3A4 inducers decrease the concentration of abemaciclib in serum
by altering intestinal/hepatic CYP 3A4 metabolism, the activity of abemaciclib can be reduced by butabarbital
when both drugs are combined, there may be a reduced effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be an increased effect of abemaciclib by p-glycoprotein -mdr1 efflux transporter  
when both drugs are combined, there may be an increased effect of abemaciclib by affecting hepatic or intestinal enzyme CYP3A4 metabolism  
when both drugs are combined, there may be an increased effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be an increased effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be an increased effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be an increased effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be an increased effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be an increased immunosuppressive effect of both drugs and a risk of infection  
when both drugs are combined, there may be a reduced metabolism of abemaciclib  
when both drugs are combined, there may be a reduced effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be a reduced effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism   abem
when both drugs are combined, there may be an increased effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be an increased immunosuppressive effect of both drugs and a risk of infection  
when both drugs are combined, there may be an increased effect of abemaciclib by p-glycoprotein -mdr1 efflux transporter  
when both drugs are combined, there may be an increased effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism
may increase the serum concentration of abemaciclib
may increase the serum concentration of abemaciclib
may increase the serum concentration of abemaciclib
may increase the serum concentration of abemaciclib
may increase the serum concentration of abemaciclib
CYP3A4 Inhibitors (Moderate) may increase the serum concentration when combined with Abemaciclib
it may diminish the metabolism when combined with zuclopenthixol
it may increase the levels of serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates
it may increase the levels of serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates
it may increase the levels of serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates
it may increase the levels of serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates
it may increase the levels of serum concentration of OATP1B1/1B3 (SLCO1B1/1B3) Substrates
combining netupitant with abemaciclib can result in an increase in the concentration serum of abemaciclib
The serum concentration of abemaciclib can be elevated when used together with mibefradil
The combination of troleandomycin may lead to a reduced metabolism of abemaciclib
When abemaciclib is used together with capsaicin, this leads to enhanced risk or seriousness of methemoglobinemia
abemaciclib: they may enhance the serum concentration of metformin
methoxypolyethylene glycol-epoetin betaÂ
using a combination of acemaciclib and methoxy polyethylene glycol-epoetin beta can raise the risk or severity of thrombosis
the metabolism of abemaciclib can decrease when combined with dihydroergocristine
When abemaciclib is used together with oleandomycin, this leads to enhanced concentration serum of abemaciclib
When abemaciclib is used together with ridaforolimus, this leads to enhanced concentration serum of abemaciclib
When abemaciclib is used together with patupilone, this leads to enhanced concentration serum of abemaciclib
the metabolism of abemaciclib can be accelerated when combined with sulfinpyrazone
the serum concentration of abemaciclib may experience an increase when combined with ivacaftor
the combined use of cinchocaine and abemaciclib results in a greater risk of methemoglobinemia
taurocholic acid has the potential to reduce the excretion rate of abemaciclib, resulting in an elevated serum level
abemaciclib: it may decrease the metabolism of barnidipine
its metabolism may be slowed down when used with dalfopristin
the abemaciclib serum concentration can be raised when it is combined with fostamatinib
When combined with diethylstilbestrol, the serum levels of abemaciclib can be increased
the concentration of abemaciclib in the bloodstream can be raised when combined with filgotinib
dengue vaccine efficacy will be reduced by abemaciclib by immunosuppression
when both drugs are combined, there may be an increased effect of abemaciclib by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
when both drugs are combined, there may be an increased level or effect of abemaciclib  
fedratinib increases the effect of abemaciclib by altering the intestinal/ hepatic CYP3A4 enzyme metabolism
idelalisib increases the effect or level of abemaciclib by altering the intestinal/hepatic CYP3A4 metabolism
CYP3A4 inhibitors increase the concentration of abemaciclib in serum
may enhance the serum concentration of CYP3A4 inhibitors
may decrease the serum concentration of CYP3A4 Inducers
may increase the levels of serum concentration
may increase the levels of serum concentration
may increase the levels of serum concentration
may increase the levels of serum concentration
may increase the levels of serum concentration
may enhance the serum concentration of metformin
may decrease the levels of serum concentration
may decrease the levels of serum concentration
may decrease the levels of serum concentration
may decrease the levels of serum concentration
may decrease the levels of serum concentration
may increase the levels of serum concentration
may increase the levels of serum concentration
may increase the levels of serum concentration
may increase the levels of serum concentration
may increase the levels of serum concentration
when coupled with asunaprevir, abemaciclib's serum levels can rise
the rate of metabolism of abemaciclib may be reduced
the risk of methemoglobinemia may be increased
the serum levels of abemaciclib may be increased
the serum levels of abemaciclib may be increased
the serum levels of abemaciclib may be increased
the serum levels of abemaciclib may be increased
the risk of methemoglobinemia may be increased
there may be a rise in abemaciclib's serum levels when coupled with carbomycin
its metabolism may be slowed down when used with quinupristin
an increase in the serum concentration of abemaciclib may occur when combined with rokitamycin
Cell cycle regulation is essential for controlled cell growth, and its disruption can lead to cancer. A key checkpoint is the G1 to S phase transition, controlled by the retinoblastoma protein (Rb). CDK4/6, when bound to D-type cyclins, phosphorylate Rb, allowing E2F transcription factors to activate genes for DNA synthesis and cell cycle progression. Abemaciclib inhibits CDK4/6, preventing Rb phosphorylation, causing G1 arrest and reducing cell proliferation—especially in Rb-positive cells. It is more selective for CDK4 than CDK6, unlike other CDK inhibitors.Â
Adverse drug reactions: Â
Frequency defined Â
>10% Â
Increased creatinine Â
Decreased white blood cell count Â
decreased neutrophil count Â
anemia Â
decreased lymphocyte count Â
decreased platelet count Â
neutropenia Â
Leukopenia Â
Thrombocytopenia Â
Diarrhea Â
nausea Â
abdominal pain Â
vomiting Â
constipation Â
stomatitis Â
dry mouth   Â
Fatigue Â
infections Â
peripheral edema Â
Pyrexia Â
1-10% Â
Interstitial lung disease Â
Pneumonitis Â
Arthralgia Â
Venous thromboembolic events
There are no black box warningsÂ
Contraindications:Â
Hypersensitivity Â
CautionsÂ
Hepatic impairment: Dose adjustment recommended in severe hepatic dysfunction.Â
Infection risk: Monitor for signs of infection and neutropenia.Â
Patients with history of thromboembolic eventsÂ
Pregnancy warnings:   Â
Breastfeeding warnings:Â
Pregnancy Categories:     Â
It is an antitumor agent used primarily for the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer. Its pharmacological action is based on selective inhibition of cyclin-dependent kinases 4 and 6 (CDK4 and CDK6), key enzymes that regulate the cell cycle. By inhibiting CDK4 and CDK6, abemaciclib disrupts the progression of the cell cycle from the G1 to the S phase, thereby preventing cancer cell proliferation driven by unregulated CDK activity. This targeted mechanism helps to slow tumor growth and proliferation in cancers dependent on these pathways.Â
PharmacokineticsÂ
AbsorptionÂ
Abemaciclib has an oral bioavailability of 45% following a single 200-mg dose, with peak plasma concentrations occurring approximately 8 hours after administration. When taken with a high-fat, high-calorie meal, the area under the plasma concentration-time curve (AUC) increases by 9%, and the peak plasma concentration (Cmax) rises by 26%.Â
DistributionÂ
The drug is highly protein-bound, with 96.3% binding for abemaciclib itself, and its metabolites M2, M18, and M20 showing protein binding of 93.4%, 96.8%, and 97.8%, respectively. Abemaciclib has a large volume of distribution of about 690.3 liters.Â
MetabolismÂ
It is primarily metabolized in the liver by the enzyme CYP3A4 into several metabolites, including N-desethylabemaciclib (M2), hydroxy-N-desethylabemaciclib (M18), hydroxyabemaciclib (M20), and an oxidative metabolite (M1). The metabolites M2, M18, and M20 are equipotent to the parent drug and collectively contribute substantially to the total circulating drug exposure, accounting for 25%, 13%, and 26% of the plasma AUC, respectivelyÂ
Elimination/ExcretionÂ
Excretion of abemaciclib occurs mainly through the feces, accounting for 81% of the administered dose primarily as metabolites, while urinary excretion represents about 3% of the dose.Â
PharmacodynamicsÂ
When combined with fulvestrant, abemaciclib extended progression-free survival to 16.4 months in patients with HR-positive, HER2-negative breast cancer, compared to 9.3 months with fulvestrant plus placebo. As a single agent, abemaciclib led to complete or partial tumor shrinkage in 19.7% of patients, with a median duration of response lasting 8.6 months. It works by causing cell cycle arrest and demonstrating antitumor effects in human tumor xenograft models. Additionally, studies in patients and healthy volunteers have shown that abemaciclib does not cause significant changes in the QTc interval.Â
Abemaciclib is taken orally, with or without food, once daily at the same time. Tablets should be swallowed whole and not crushed or broken. If a dose is missed or vomiting occurs, take the next dose as scheduled. Store at 20–25°C, with allowable variation between 15–30°C.Â
Generic Name: abemaciclibÂ
Pronunciation: a-BEM-a-sye-klibÂ
Abemaciclib is an anti-cancer agent used to treat breast cancer that may spread along with the lymph nodes of the armpit.
For the caution, abemaciclib may reduce the WBCs and put you at greater risk of infection. It may also cause blood clots in veins, affect liver functionality, and cause diarrhea.
This drug is not suitable for adolescents and children below 18 years.
The recommended dosage for breast cancer therapy is 150 mg orally twice daily.
The treatment of abemaciclib should last for two years.
Common side effects of abemaciclib may include dry skin, muscle weakness, watery eyes, indigestion, splitting of nails and inflammation in the lungs, hair loss, and decreased appetite.
Do not take a double dose if you miss a dose; take the next one at the usual time.
Keep the medicine out of reach of children. There are no special conditions required for storage.
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