Please assess the completion status of the following clinical trial:

Trial Title: Tizanidine and Superficial Cervical Block on Pain After Thyroidectomy

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: DOUBLE
- Phase: PHASE4
- Number of Arms: 3.0

Eligibility Criteria:
Inclusion Criteria:~* American Society of Anesthesiologist's physiologic state I-III patients undergoing thyroidectomy~Exclusion Criteria:~* chronic pain~* bleeding disorders~* renal or hepatic insufficiency~* patients on chronic non-steroidal anti-inflammatory medications~* recurrent goiter~* emergency cases

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 65 Years
- Healthy Volunteers: f

Study Arms:
- Placebo (Type: PLACEBO_COMPARATOR): Group Placebo (Group P) will receive placebo 1 hour before surgery and bilateral superficial cervical block with saline 10 ml each side
- Tizanidine (Type: EXPERIMENTAL): Group Tizanidine (Group T) will receive 6 mg tizanidine 1 hour before surgery and bilateral superficial cervical block with %0.25 bupivacaine 10ml each side
- Bupivacaine (Type: ACTIVE_COMPARATOR): Group Bupivacaine will receive placebo 1 hour before surgery and bilateral superficial cervical block with %0.25 bupivacaine 10ml each side

Based on this trial design, predict the completion outcome and termination type (if applicable).